International Journal of Pharmaceutics (v.509, #1-2)
EDITORIAL BOARD (iii).
In vitro anti-Acanthamoeba synergistic effect of chlorhexidine and cationic carbosilane dendrimers against both trophozoite and cyst forms by I. Heredero-Bermejo; J. Sánchez-Nieves; J. Soliveri; R. Gómez; F.J. de la Mata; J.L. Copa-Patiño; J. Pérez-Serrano (1-7).
Combinations of chlorhexidine with ammonium and guanidine carbosilane dendrimers have remarkable cooperative effect against trophozoites and cysts of Acanthamoeba polyphaga.Display Omitted Acanthamoeba sp. are the causative agents of severe illnesses in humans such as Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). Medical therapy is not yet well established. Treatments of AK last for several months and generate toxicity, resistances appear due to the cysts stage and recurrences can occur. In this study has been demonstrated that the combination of chlorhexidine digluconate (CLX) and carbosilane dendrimers containing ammonium or guanidine moieties has in vitro synergistic effect against Acanthamoeba polyphaga. This synergy provokes an important reduction in the minimal trophozoite amoebicidal concentration (MTAC) of CLX, which means a reduction of their toxic effects on human cells. Moreover, some CLX/dendrimer combinations show important activity against the cyst resistance stage.
Keywords: Acanthamoeba; Drug resistance; Acanthamoeba keratitis; Carbosilane dendrimers; Chlorhexidne; Microbicide; Synergy;
Hybrid systems based on “drug – in cyclodextrin – in nanoclays” for improving oxaprozin dissolution properties by Paola Mura; Francesca Maestrelli; Carola Aguzzi; César Viseras (8-15).
Display OmittedA combined approach based on drug complexation with cyclodextrins, and complex entrapment in nanoclays has been investigated, to join in a single delivery system the benefits of these carriers and potentiate their ability to improve the dissolution properties of oxaprozin (OXA), a poorly water-soluble anti-inflammatory drug. Based on previous studies, randomly methylated ß-cyclodextrin (RAMEB) was chosen as the most effective cyclodextrin for OXA complexation. Adsorption equilibrium studies performed on three different clays (sepiolite, attapulgite, bentonite) allowed selection of sepiolite (SV) for its greater adsorption power towards OXA. DSC and XRPD studies indicated drug amorphization in both binary OXA-RAMEB coground and OXA-SV cofused products, due to its complexation or very fine dispersion in the clay structure, respectively. The drug amorphous state was maintained also in the ternary OXA-RAMEB-SV cofused system. Dissolution studies evidenced a clear synergistic effect of RAMEB complexation and clay nanoencapsulation in improving the OXA dissolution properties, with an almost 100% increase in percent dissolved and dissolution efficiency compared to the OXA-RAMEB coground system. Therefore, the proposed combined approach represents an interesting tool for improving the therapeutic effectiveness of poorly soluble drugs, and reducing the CD amount necessary for obtaining the desired drug solubility and dissolution rate increase.
Keywords: Cyclodextrin complexation; Nanoclays; Oxaprozin; Sepiolite; Clay-cyclodextrin hybrid systems;
Bioconjugated gold nanoparticles enhance cellular uptake: A proof of concept study for siRNA delivery in prostate cancer cells by Jianfeng Guo; Caitriona M. O’Driscoll; Justin D. Holmes; Kamil Rahme (16-27).
Display OmittedThe chemistry of gold nanoparticles (AuNPs) facilitates surface modifications and thus these bioengineered NPs have been investigated as a means of delivering a variety of therapeutic cargos to treat cancer. In this study we have developed AuNPs conjugated with targeting ligands to enhance cell-specific uptake in prostate cancer cells, with a purpose of providing efficient non-viral gene delivery systems in the treatment of prostate cancer. As a consequence, two novel AuNPs were synthesised namely AuNPs-PEG-Tf (negatively charged AuNPs with the transferrin targeting ligands) and AuNPs-PEI-FA (positively charged AuNPs with the folate-receptor targeting ligands). Both bioconjugated AuNPs demonstrated low cytotoxicity in prostate cancer cells. The attachment of the targeting ligand Tf to AuNPs successfully achieved receptor-mediated cellular uptake in PC-3 cells, a prostate cancer cell line highly expressing Tf receptors. The AuNPs-PEI-FA effectively complexed small interfering RNA (siRNA) through electrostatic interaction. At the cellular level the AuNPs-PEI-FA specifically delivered siRNA into LNCaP cells, a prostate cancer cell line overexpressing prostate specific membrane antigen (PSMA, exhibits a hydrolase enzymic activity with a folate substrate). Following endolysosomal escape the AuNPs-PEI-FA.siRNA formulation produced enhanced endogenous gene silencing compared to the non-targeted formulation. Our results suggest both formulations have potential as non-viral gene delivery vectors in the treatment of prostate cancer.
Keywords: Gold nanoparticles; Targeting ligands; Receptor-mediated internalisation; Non-viral siRNA delivery; Prostate cancer gene therapy;
Hepatotoxicity evaluation of dextran stabilized iron oxide nanoparticles in Wistar rats by Sheeja Liza Easo; P.V. Mohanan (28-34).
Display OmittedCellular and organ responses to nanoparticles are relevant in the context of use of nanoparticles for biomedical applications. The purpose of the present study was to determine the potential of dextran stabilized iron oxide nanoparticles (DIONPs) to influence hepatic uptake and consequently induce hepatotoxic response in rats following intravenous administration. Inductively coupled plasma atomic emission spectroscopy analysis revealed that DIONPs are rapidly taken up into the liver, progressively broken down to iron constituents and exported into blood, with a part of it being retained in the liver. The potential of DIONPs to induce oxidative stress response was determined by evaluating the time-dependent redox defense status. Maximum alterations in antioxidant activities were observed to occur within a period of 7 days. However, this effect was not followed by significant increase in lipid peroxidation or modulation of hepatic enzymes such as alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase and bilirubin levels. Overall, these data imply that the liver retains functional integrity with a dose of 10 mg/kg DIONPs, although with brief activation of redox defenses.
Keywords: Iron oxide nanoparticles; Liver; Oxidative stress; Antioxidant enzymes; Lipid peroxidation;
Commonality between BCS and TCS by Vinod P. Shah; Flavian Ştefan Rădulescu; Dalia Simona Miron; Avraham Yacobi (35-40).
Display OmittedBoth biopharmaceutics classification system (BCS) and topical drug classification system (TCS) are based on sound scientific principles with the aim of providing biowaiver and reducing regulatory burden without lowering the quality requirements and standards of approval for the drug products. BCS is based on the solubility and permeability properties of the active pharmaceutical ingredient (API, or drug substance) whereas the TCS is based on the qualitative and quantitative composition of the dosage form and the in vitro release rate of the active ingredient as key decision tools. Both BCS and TCS take drug release and dissolution as their guiding principle for providing biowaiver, increasing the availability and affordability of safe and effective medicines to the consumers and at the same time maintaining the drug product quality.
Keywords: In vitro release; Biowaiver; Topical drug classification system; BCS; TCS;
Suppression of protein inactivation during freezing by minimizing pH changes using ionic cryoprotectants by Ľubica Krausková; Jitka Procházková; Martina Klašková; Lenka Filipová; Radka Chaloupková; Stanislav Malý; Jiří Damborský; Dominik Heger (41-49).
Display OmittedFreezing and lyophilization are often used for stabilization of biomolecules; however, this sometimes results in partial degradation and loss of biological function in these molecules. In this study we examined the effect of freezing-induced acidity changes on denaturation of the model enzyme haloalkane dehalogenase under various experimental conditions. The effective local pH of frozen solutions is shown to be the key causal factor in protein stability. To preserve the activity of frozen-thawed enzymes, acidity changes were prevented by the addition of an ionic cryoprotectant, a compound which counteracts pH changes during freezing due to selective incorporation of its ions into the ice. This approach resulted in complete recovery of enzyme activity after multiple freeze-thaw cycles. We propose the utilization of ionic cryoprotectants as a new and effective cryopreservation method in research laboratories as well as in industrial processes.
Keywords: Protein cryopreservation; Freezing/thawing; Protein aggregation; Protein stability; Quality by design; Freezing stress; Freezing-induced pH shift;
Evaluation of dry powder inhalers with a focus on ease of use and user preference in inhaler-naïve individuals by Sofia von Schantz; Nina Katajavuori; Osmo Antikainen; Anne Juppo (50-58).
Display OmittedInhaler errors are common amongst inhaler users. Therefore, in the development work of new inhalation devices, it is important to characterize the ease of use of the inhalers. In this study four dry powder inhalers, Diskus, Easyhaler, Ellipta and Turbuhaler, were evaluated, focusing on ease of use and patient preference. The study used a triangular methodology. The sample consisted of 31 inhaler naïve individuals. Educational videos for all inhalers were watched, and afterwards, the use of all four inhalers was demonstrated in a random order. The demonstrations were videotaped. Thereafter they were checked against a predefined checklist and all mistakes were recorded. Only 33% of inhaler demonstrations were completed without the participants making any mistakes. The proportions of subjects who used the devices correctly were as follows: Diskus 48%, Easyhaler 19%, Ellipta 55% and Turbuhaler 16%. When comparing correct and incorrect inhaler technique for each inhaler pair the following differences were statistically significant: Diskus vs. Easyhaler (p < 0.05), Ellipta vs. Easyhaler (p < 0.01), Diskus vs. Turbuhaler (p < 0.01), Ellipta vs. Turbuhaler (p < 0.01). In the participants’ ranking, the inhalers Ellipta, followed by Turbuhaler, were most often ranked as most preferred. Participants’ preference of Ellipta over Easyhaler (p < 0.01) and over Diskus (p < 0.001) were statistically significant.
Keywords: Dry powder inhaler; Preference; Ease of use; Inhalation errors;
Particulate systems based on pectin/chitosan association for the delivery of manuka honey components and platelet lysate in chronic skin ulcers by Marika Tenci; Silvia Rossi; Maria Cristina Bonferoni; Giuseppina Sandri; Cinzia Boselli; Arianna Di Lorenzo; Maria Daglia; Antonia Icaro Cornaglia; Luciana Gioglio; Cesare Perotti; Carla Caramella; Franca Ferrari (59-70).
Display OmittedThe aim of the present work was the development of a powder formulation for the delivery of manuka honey (MH) bioactive components and platelet lysate (PL) in chronic skin ulcers. In particular pectin (PEC)/chitosan (CS) particles were prepared by ionotropic gelation in the presence of calcium chloride and subsequently characterized for particle size, hydration properties and mechanical resistance. Different experimental conditions (calcium chloride and CS concentrations; rest time in the cationic solution) were considered in order to obtain particles characterized by optimal size, hydration properties and mechanical resistance. Two different fractions of MH were examined: one (Fr1), rich in methylglyoxal and the other (Fr2), rich in polyphenols.Particles were loaded with Fr1, fraction able to enhance in vitro proliferation of human fibroblasts, and with PL. The presence of CS in Fr1-loaded particles produced an improvement in cell proliferation. Moreover, PL loading into particles did not affect the biological activity of the hemoderivative. In vivo efficacy of PL- and Fr1-loaded particles was evaluated on a rat wound model. Both treatments markedly increased wound healing to the same extent.
Keywords: Wound healing; Polymeric particles; Pectin; Chitosan; Manuka honey; Platelet lysate;
Optimisation of vectorisation property: A comparative study for a secondary amphipathic peptide by Karidia Konate; Mattias F. Lindberg; Anaïs Vaissiere; Carole Jourdan; Gudrun Aldrian; Emmanuel Margeat; Sébastien Deshayes; Prisca Boisguerin (71-84).
Display OmittedRNA interference provides a powerful technology for specific gene silencing. Therapeutic applications of small interfering RNA (siRNA) however require efficient vehicles for stable complexation and intracellular delivery. In order to enhance their cell delivery, short amphipathic peptides called cell-penetrating peptides (CPPs) have been intensively developed for the last two decades. In this context, the secondary amphipathic peptide CADY has shown to form stable siRNA complexes and to improve their cellular uptake independent of the endosomal pathway. In the present work, we have described the parameters influencing CADY nanoparticle formation (buffers, excipients, presence of serum, etc.), and have followed in details the CPP:siRNA self-assembly. Once optimal conditions were determined, we have compared the ability of seven different CADY analogues to form siRNA-loaded nanoparticles compared to CADY:siRNA. First of all, we were able to show by biophysical methods that structural polymorphism (α-helix) is an important prerequisite for stable nanoparticle formation independently of occurring sequence mutations. Luciferase assays revealed that siRNA complexed to CADY-K (shorter version) shows better knock-down efficiency on Neuro2a-Luc+ and B16-F10-Luc+ cells compared to CADY:siRNA. Altogether, CADY-K is an ideal candidate for further application especially with regards to ex vivo or in vivo applications.
Keywords: Cell penetrating peptide; siRNA; Nanoparticle; Self-assembly; Luciferase assay; Fluorescence correlation spectroscopy; Circular dichroism; Dynamic light scattering;
Ear Cubes for local controlled drug delivery to the inner ear by M. Gehrke; J. Sircoglou; D. Gnansia; G. Tourrel; J.-F. Willart; F. Danede; E. Lacante; C. Vincent; F. Siepmann; J. Siepmann (85-94).
Display OmittedA new type of advanced drug delivery systems is proposed: Miniaturized implants, which can be placed into tiny holes drilled into (or close to) the oval window. They consist of two parts: 1) A cylinder, which is inserted into the hole crossing the oval window. The cylinder (being longer than the depth of the hole) is partly located within the inner ear and surrounded by perilymph. This provides direct access to the target site, and at the same time assures implant fixation. 2) A cuboid, which is located in the middle ear, serving as a drug reservoir. One side of the cuboid is in direct contact with the oval window. Drug release into the cochlea occurs by diffusion through the cylindrical part of the Ear Cubes and by diffusion from the cuboid into and through the oval window. High precision molds were used to prepare two differently sized Ear Cubes by injection molding. The miniaturized implants were based on silicone and loaded with different amounts of dexamethasone (10 to 30 % w/w). The systems were thoroughly characterized before and upon exposure to artificial perilymph at 37 °C. Importantly, drug release can effectively be controlled and sustained during long time periods (up to several years). Furthermore, the implants did not swell or erode to a noteworthy extent during the observation period. Drug diffusion through the polymeric matrix, together with limited dexamethasone solubility effects, seem to control the resulting drug release kinetics, which can roughly be estimated using mathematical equations derived from Fick’s second law. Importantly, the proposed Ear Cubes are likely to provide much more reliable local long term drug delivery to the inner ear compared to liquid or semi-solid dosage forms administered into the middle ear, due to a more secured fixation. Furthermore, they require less invasive surgeries and can accommodate higher drug amounts compared to intracochlear implants. Thus, they offer the potential to open up new horizons for innovative therapeutic strategies to treat inner ear diseases and disorders.
Keywords: Implant; Silicone; Cochlea; Local controlled drug delivery; Mathematical modeling;
Dealing with nanosafety around the globe—Regulation vs. innovation by Matthias G. Wacker; Ana Proykova; Gustavo Mendes Lima Santos (95-106).
Display OmittedIn recent years, nanotechnology has become increasingly important for global industries. Today, many nanomaterials are used as ingredients in cosmetics, food products, medical devices and pharmaceuticals. In some cases they exert unexpected risks and potentially pose a threat to human health and the environment.Regulatory authorities all over the world carefully observe recent developments in this area, striving to find a balance between consumer safety and the interests of the industry.In the following, the current legislation in the United States of America, the European Union, Asia and Brazil will be presented. Further, the requirements defined by these different authorities and methodology to investigate relevant characteristics of nanomaterials will be discussed.
Keywords: Nanomaterials; Nanoparticles; Regulations; EMA; ANVISA; EFSA; OECD; Rules; Law;
Polyaminoacid nanocapsules for drug delivery to the lymphatic system: Effect of the particle size by Raquel Abellan-Pose; Carmen Teijeiro-Valiño; Manuel J. Santander-Ortega; Erea Borrajo; Anxo Vidal; Marcos Garcia-Fuentes; Noémi Csaba; María José Alonso (107-117).
Display OmittedPrevious work by our group showed the possibility to reduce the toxicity of docetaxel upon its encapsulation in polyaminoacid nanocapsules with a size of 200 nm. The objective of this study was to elucidate whether a reduction in the nanocapsules size might facilitate their access to the lymphatic system. To do so, we analyzed the effect of several formulation parameters on the characteristics of polyglutamic acid, PEGylated polyglutamic acid and polyasparagine nanocapsules. From these experiments, we could identify the best conditions to produce nanocapsules with a small size (close to 100 nm) and adequate capacity to encapsulate and sustain the release of the antitumor drug docetaxel. Moreover, the results of the stability study made evident the critical role of the polyaminoacid shell on the colloidal stability of the nanocapsules in biologically relevant media. Finally, we studied the influence of the particle size (100 nm vs. 200 nm) on the biodistribution of PGA-PEG nanocapsules following subcutaneous injection. The results showed that the 100 nm-size nanocapsules accumulate faster in the lymph nodes, than those with a size of 200 nm. In summary, these data suggest the potential of 100 nm-size polyaminoacid nanocapsules as lymphatic drug delivery carriers.
Keywords: Lymphatic targeting; Polyaminoacid nanocapsules; Particle size;
Effect of particle size on their accumulation in an inflammatory lesion in a dextran sulfate sodium (DSS)-induced colitis model by Ayaka Watanabe; Hiroki Tanaka; Yu Sakurai; Kota Tange; Yuta Nakai; Tatsuya Ohkawara; Hiroshi Takeda; Hideyoshi Harashima; Hidetaka Akita (118-122).
Display OmittedTaking advantage of the enhanced permeation and retention (EPR) effect is a promising approach for delivering macromolecules or nanoparticles to tumors. Recent studies revealed that this strategy is also applicable for targeting other pathological lesions (i.e. inflammatory disease). In the present study, we report the optimal size of a nanoparticle for allowing the higher accumulation of a particle in an inflammatory lesion using a dextran sulfate sodium (DSS)-induced colitis model. As a nanoparticle platform, we utilized a SS-cleavable and pH-activated lipid-like material (ssPalm), that can be used to produce particles in a variety of sizes ranging from 50 nm to 180 nm while using the same lipid composition. In healthy mice, particle accumulation remained low regardless of size. In contrast, the accumulation in inflammatory colon tissue was enhanced depending on the progress of the inflammation. In this situation, the apparent uptake clearance accumulation of a mid-sized particle (113 nm on average) was higher than that for smaller and larger (54 nm and 183 nm in average, respectively) ones. Therefore, controlling particle size is an important parameter for the extensive targeting of inflammatory lesion.
Keywords: Colitis; Inflammation; Nanoparticles; Accumulation; ssPalm;
Continuous feeding of low-dose APIs via periodic micro dosing by M.O. Besenhard; S.K. Karkala; E. Faulhammer; S. Fathollahi; R. Ramachandran; J.G. Khinast (123-134).
Display OmittedPrecise and effective feeding of small powder quantities remains a challenge in many fields, including pharmaceutical development and production. This paper demonstrates that a simple feeding principle can be applied to accomplish stable micro feeding (<100 mg/s) and describes a gravimetric powder feeding system with a vibratory sieve mounted on a chute. Feeding was induced via vertical vibrations that can be adjusted within a broad range of frequencies and amplitudes. The feeding system was studied using different frequencies, amplitudes, sieves and powder properties. Feeding was characterized by means of a dynamic scale and high-speed camera recordings. The feeding system provided effective powder feeding even in a range of 1–2 mg/s. It was shown that powder properties require special attention when the vibratory sieve-chute system operates at higher feed rates (or feeding times >30 min), i.e., feeding at a higher throughput.A combination of discrete element method (DEM) simulations and compartment population balance model (PBM) was used to incorporate the proposed micro feed system into a continuous powder mixer (Gerike GCM250; Gerike Holding LTD., Regensdorf, Switzerland). It illustrates how oscillating feeding rates (the latter is a characteristic of the studied micro feeding system) affect the content uniformity of low dose blends, i.e., powder mixtures with a relatively low fraction of active pharmaceutical ingredient.
Keywords: Powder feeding; Micro feeding; Continuous blending; Vibratory sieve; Feed rate robustness; DEM; Compartment model;
Role of moisture on the physical stability of polymorphic olanzapine by Maria C. Paisana; Martin A. Wahl; João F. Pinto (135-148).
Display OmittedThe focus of this study was the understanding of the hydrate transformations of anhydrous olanzapine Forms I and II (the most common polymorphs) upon exposure to different moisture conditions (11, 53, 75, 93% RH) and direct contact with water (e.g. aqueous slurry) and the impact of hydration on the aqueous dissolution rates of the polymorphs. The kinetics of reversible transformations (anhydrate-hydrate phases) and the identification of polymorphs were evaluated by differential scanning calorimetry, thermogravimetry, infrared (DRIFT) and X-ray powder diffraction. The results showed that anhydrous Forms I and II have undergone water vapor phase induced transformations at 93% and 75% RH, respectively. At 93% RH Forms I and II showed to hydrate into dihydrates D and B, respectively, the latter with a higher hydration rate. The conversion of Form I into the dihydrate D showed to affect the dissolution rate of olanzapine (f2 < 50). As slurries both forms showed to hydrate into a mixture of two different Forms – dihydrate B and higher hydrate. The study provided an understanding of the conversion pathways of the different forms when they were exposed to humid air or aqueous environments, resembling the transformations that might occur during processing, storage or during the persecution of dissolution tests to assess the quality of dosage forms delivering olanzapine.
Keywords: Dissolution; Hydrate/solvate; Olanzapine; Polymorphism; Solid state; Water sorption;
Design of cholesterol arabinogalactan anchored liposomes for asialoglycoprotein receptor mediated targeting to hepatocellular carcinoma: In silico modeling, in vitro and in vivo evaluation by Pankaj Pathak; Vivek Dhawan; Aniket Magarkar; Reinis Danne; Srinath Govindarajan; Sandipto Ghosh; Frank Steiniger; Pradip Chaudhari; Vijaya Gopal; Alex Bunker; Tomasz Róg; Alfred Fahr; Mangal Nagarsenker (149-158).
Display OmittedWe have developed active targeting liposomes to deliver anticancer agents to ASGPR which will contribute to effective treatment of hepatocellular carcinoma. Active targeting is achieved through polymeric ligands on the liposome surface. The liposomes were prepared using reverse phase evaporation method and doxorubicin hydrocholoride, a model drug, was loaded using the ammonium sulphate gradient method. Liposomes loaded with DOX were found to have a particle size of 200 nm with more than 90% entrapment efficiency. Systems were observed to release the drug in a sustained manner in acidic pH in vitro. Liposomes containing targeting ligands possessed greater and selective toxicity to ASGPR positive HepG2 cell lines due to specific ligand receptor interaction. Bio-distribution studies revealed that liposomes were concentrated in the liver even after 3 h of administration, thus providing conclusive evidence of targeting potential for formulated nanosystems. Tumor regression studies indicated greater tumor suppression with targeted liposomes thereby establishing superiority of the liposomal system. In this work, we used a novel methodology to guide the determination of the optimal composition of the targeting liposomes: molecular dynamics (MD) simulation that aided our understanding of the behaviour of the ligand within the bilayer. This can be seen as a demonstration of the utility of this methodology as a rational design tool for active targeting liposome formulation.
Keywords: Cholesterol; Hepatocellular carcinoma; Liposomes; Targeting; Asialoglycoprotein receptor; Arabinogalactan; Simulations;
Doxorubicin loaded large-pore mesoporous hydroxyapatite coated superparamagnetic Fe3O4 nanoparticles for cancer treatment by Negar Abbasi Aval; Jalil Pirayesh Islamian; Milad Hatamian; Mohammad Arabfirouzjaei; Jafar Javadpour; Mohammad-Reza Rashidi (159-167).
Display OmittedIn the present study, a series of multifunctional drug delivery systems based on mesostructured hydroxyapatite coating and superparamagnetic nanoparticles with pH-responsive characters was prepared. The structure of each new synthesized nanoscale composite was fully characterized by XRD, FTIR, TEM, VSM and BET. The results showed a good ordered mesostructure having large pores, high pore volume, high surface area, and varied super paramagnetic properties. The mesoporous hydroxyapatite coated super paramagnetic Fe3O4 nanoparticles were applied as a drug delivery carrier loaded with doxorubicin (DOX) as a model drug. The storage/release properties of the developed nonocarriers in phosphate buffer saline (PBS) were studied in two certain pHs: pH = 7.4 (the human blood pH) and pH = 5.5 (pH of cancer cells). The large pores in the synthesized mesoporous acted as an excellent carrier for DOX molecules with a loading efficiency of ≈93% which is much higher than that of the conventional hydroxyapatite particles. When the pH of the release medium (PBS) was changed from 7.4 to 5.5, the drug release increased significantly from 10% of the adsorbed drug to about 70%. DOX-loaded mesostructure hydroxyapatite reduced the viability of SKBR3 and T47D cells by 54.7 and 57.3%, respectively, which were very similar to 56.8 and 60.4% reduction resulted from free DOX incubation. This new drug delivery system which benefits from both super paramagnetic properties and pH-responsive performances may serve as a suitable platform for developing new biocompatible drug carriers and could have a good potential use in targeted cancer therapy.
Keywords: Mesoporous hydroxyapatite; Superparamagnetic iron oxide nanoparticles; Drug delivery system; Doxorubicin; Cancer treatment;
In vitro and in vivo evaluation of stimuli-responsive vesicle from PEGylated hyperbranched PAMAM-doxorubicin conjugate for gastric cancer therapy by Jinshan Nie; Yang Wang; Wei Wang (168-177).
Display OmittedGastric Cancer is one of the major leading causes of death by cancer worldwide, but the chemotherapeutics, one of the preferred approaches, bring about extensive side effects when systemically injected. In our work, doxorubicin-loaded pH and redox responsive hyperbranched poly(amidoamine)(h-PAMAM)-based vesicle was prepared to enhance anti-tumor efficacy of chemotherapeutic compounds. The doxorubicin (DOX) molecules were attached to PEGylated h-PAMAM by acid sensitive cis-aconityl linkage to form pH sensitive conjugate (PPCD), which self-assembled in THF into micelles. The resulted micelles were then crosslinked by disulfide bonds and transferred from THF into water to form vesicles, which could be disassembled into small-sized conjugates under the redox condition. The drug release profiles showed that the PPCD vesicle presented stimuli-triggered drug release in acidic and reducing environment, and lower DOX leakage under neutral condition. The in vitro cell assay reflected the rapid DOX release and significant tumor-cytotoxic effect of the PPCD vesicle. The in vivo anticancer activity and systematic toxicity studies showed that the PPCD vesicles had lower tissue toxicity with good antitumor effect. In brief, h-PAMAM-based PPCD vesicle provides a safe and effective drug delivery system for the therapy of gastric cancer.
Keywords: Vesicle; Disulfide-bonded; Cis-aconityl; PEGylation; Hyperbranched poly(amidoamine);
Anti-tumor effect via passive anti-angiogenesis of PEGylated liposomes encapsulating doxorubicin in drug resistant tumors by Golam Kibria; Hiroto Hatakeyama; Yusuke Sato; Hideyoshi Harashima (178-187).
Display OmittedThe PEGylated liposomal (PEG-LP) Doxorubicin, PEG-LP (DOX), with a diameter of around 100 nm, accumulates in tumors via the enhanced permeability and retention (EPR) effect, and is used clinically for the treatment of several types of cancer. However, there are a number of tumor types that are resistant to DOX. We report herein on a unique anti-tumor effect of PEG-LP (DOX) in a DOX-resistant tumor xenograft model. PEG-LP (DOX) failed to suppress the growth of the DOX-resistant tumors (ex. non-small cell lung cancer, H69AR; renal cell carcinoma, OSRC-2) as observed in the xenograft model. Unexpectedly, tumor growth was suppressed in a DOX-resistant breast cancer (MDA-MB-231) xenograft model. We investigated the mechanism by which PEG-LP (DOX) responses differ in different drug resistant tumors. In hyperpermeable OSRC-2 tumors, PEG-LP was distributed to deep tumor tissues, where it delivers DOX to drug-resistant tumor cells. In contrast, extracellular matrix (ECM) molecules such as collagen, pericytes, cancer-associated fibroblasts render MDA-MB-231 tumors hypopermeable, which limits the extent of the penetration and distribution of PEG-LP, thereby enhancing the delivery of DOX to the vicinity of the tumor vasculature. Therefore, a remarkable anti-angiogenic effect with a preferential suppression in tumor growth is achieved. Based on the above findings, it appears that the response of PEG-LP (DOX) to drug-resistant tumors results from differences in the tumor microenvironment.
Keywords: PEGylated liposome; Doxil; Drug-resistant cancer; Passive anti-angiogenesis; Anti-tumor effect;
Platelet lysate and chondroitin sulfate loaded contact lenses to heal corneal lesions by Giuseppina Sandri; Maria Cristina Bonferoni; Silvia Rossi; Alessio Delfino; Federica Riva; Antonia Icaro Cornaglia; Giorgio Marrubini; Giorgio Musitelli; Claudia Del Fante; Cesare Perotti; Carla Caramella; Franca Ferrari (188-196).
Display OmittedHemoderivative tear substitutes contain various ephiteliotrophic factors, such as growth factors (GF), involved in ocular surface homeostasis without immunogenic properties.The aim of the present work was the loading of platelet lysate into contact lenses to improve the precorneal permanence of platelet lysate growth factors on the ocular surface to enhance the treatment of corneal lesions.To this purpose, chondroitin sulfate, a sulfated glycosaminoglycan, which is normally present in the extracellular matrix, was associated with platelet lysate. In fact, chondroitin sulfate is capable of electrostatic interaction with positively charged growth factors, in particular, with bFGF, IGF, VEGF, PDGF and TGF-β, resulting in their stabilization and reduced degradation in solution. In the present work, various types of commercially available contact lenses have been loaded with chondroitin sulfate or chondroitin sulfate in association with platelet lysate to achieve a release of growth factors directly onto the corneal surface lesions. One type of contact lenses (PureVision®) showed in vitro good proliferation properties towards corneal cells and were able to enhance cut closure in cornea constructs.
Keywords: Platelet lysate; Chondroitin sulfate; Contact lenses; in vitro wound healing;
Novel polymeric micelles for drug delivery: Material characterization and formulation screening by Christine Janas; Zouhair Mostaphaoui; Ludwig Schmiederer; Johann Bauer; Matthias G. Wacker (197-207).
Display OmittedA rising number of new chemical entities that exhibit only poor aqueous solubility are identified in drug discovery processes. Polymeric micelles composed of block copolymers (BP) facilitate the delivery of such lipophilic molecules in drug therapy. Consequently, a rational screening and selection procedure for novel BP was established. Further, the interplay of polymer structure, micelle formation and drug binding was studied. Therefore seven polymers (BP001 to BP007) were synthesized from different monomer compositions resulting in nanocarriers varying in surface decoration and lipophilicity. These polymers were characterized by H1-NMR and SEC. The molecular weight was ranging between 13 and 37 kDa. The critical micelle concentration and micellar integrity in presence of human plasma were determined. Micelles were loaded with dexamethasone and characterized with regards to their size, morphology and surface charge. Polymeric micelles with a size of 49.21–236.37 nm were obtained. A half-life of 11 h was determined for five of the copolymers in presence of human plasma. Two nanocarrier formulations (BP006 and BP007) were exhibiting optimal micellar integrity in vitro and a modified release profile under biorelevant conditions. Strongest drug-polymer interaction was observed for nanocarrier compositions providing benzyl and carboxylic groups and were composed of BP006 and BP007.
Keywords: Polymeric micelles; Block copolymer synthesis; ATRP; Drug delivery; Dexamethasone;
Biocompatible Zr-based nanoscale MOFs coated with modified poly(ε-caprolactone) as anticancer drug carriers by Maria Filippousi; Stuart Turner; Karen Leus; Panoraia I. Siafaka; Eirini D. Tseligka; Matthias Vandichel; Stavroula G. Nanaki; Ioannis S. Vizirianakis; Dimitrios N. Bikiaris; Pascal Van Der Voort; Gustaaf Van Tendeloo (208-218).
Display OmittedNanoscale Zr-based metal organic frameworks (MOFs) UiO-66 and UiO-67 were studied as potential anticancer drug delivery vehicles. Two model drugs were used, hydrophobic paclitaxel and hydrophilic cisplatin, and were adsorbed onto/into the nano MOFs (NMOFs). The drug loaded MOFs were further encapsulated inside a modified poly(ε-caprolactone) with d-α-tocopheryl polyethylene glycol succinate polymeric matrix, in the form of microparticles, in order to prepare sustained release formulations and to reduce the drug toxicity. The drugs physical state and release rate was studied at 37 °C using Simulated Body Fluid. It was found that the drug release depends on the interaction between the MOFs and the drugs while the controlled release rates can be attributed to the microencapsulated formulations. The in vitro antitumor activity was assessed using HSC-3 (human oral squamous carcinoma; head and neck) and U-87 MG (human glioblastoma grade IV; astrocytoma) cancer cells. Cytotoxicity studies for both cell lines showed that the polymer coated, drug loaded MOFs exhibited better anticancer activity compared to free paclitaxel and cisplatin solutions at different concentrations.
Keywords: Metal-organic frameworks/UiO-66; UiO-67; Polymer; Drug delivery; SEM; ADF-STEM;
Pore blocking: An innovative formulation strategy for the design of alcohol resistant multi-particulate dosage forms by Simone Schrank; Nicole Jedinger; Shengqian Wu; Michael Piller; Eva Roblegg (219-228).
Display OmittedIn this work calcium stearate (CaSt) multi-particulates loaded with codeine phosphate (COP) were developed in an attempt to provide extended release (ER) combined with alcohol dose dumping (ADD) resistance. The pellets were prepared via wet/extrusion spheronization and ER characteristics were obtained after fluid bed drying at 30 °C. Pore blockers (i.e., xanthan, guar gum and TiO2) were integrated to control the uptake of ethanolic media, the CaSt swelling and consequently, the COP release. While all three pore blockers are insoluble in ethanol, xanthan dissolves, guar gum swells and TiO2 does not interact with water. The incorporation of 10 and 15% TiO2 still provided ER characteristics and yielded ADD resistance in up to 40 v% ethanol. The in-vitro data were subjected to PK simulations, which revealed similar codeine plasma levels when the medication is used concomitantly with alcoholic beverages. Taken together the in-vitro and in-silico results demonstrate that the incorporation of appropriate pore blockers presents a promising strategy to provide ADD resistance of multi-particulate systems.
Keywords: Alcohol induced dose dumping; Extrusion/spheronization; Fluid bed drying; Codeine phosphate; Calcium stearate;
In vivo residence duration of human growth hormone loaded in nanogels comprising cinnamoyl alginate, cinnamoyl Pluronic F127 and cinnamoyl poly(ethylene glycol) by Dong Youl Yoon; Jin-Chul Kim (229-236).
Display OmittedCinnamoyl alginate, cinnamoyl Pluronic F127 and cinnamoyl poly(ethylene glycol) were self-assembled into nanogel in aqueous phase. The size of nanogel was 100 nm–200 nm on TEM photos. When 1 ml of human growth hormone (hGH) solution (5 mg/ml, pH3.0) was mixed with 4 ml of the nanogel suspension (37.5 mg/ml, pH3.0), 100% of hGH was loaded in the nanogels (corresponding to specific loading of 3.33% (w hGH/w nanogel)). In the in vivo pharmacokinetics study, the substantial blood level of hGH was maintained during the entire experiment period (two weeks) after one-time injection of hGH-loaded nanogel at 0.5 mg hGH/kg body weight, and the area under curve (AUC) obtained with the one-time injection of hGH-loaded nanogel was higher than AUC obtained with daily injections of free hGH at 0.05 mg hGH/kg for 7 days. In the in vivo pharmacodynamics study, the blood level of insulin-like growth factor (IGF-1) increased in 2 h and it was maintained during the entire experiment period (two weeks) after one-time injection of hGH-loaded nanogel at 0.5 mg hGH/kg body weight. The in vivo fluorescence images of mice injected with rhodamine B isothiocyanate-labelled nanogel suspension showed fluorescence intensity up to 96 h after intravenous injection, indicating that the in vivo residence time of the nanogel was greater than 96 h.
Keywords: Human growth hormone; Nanogel; Pharmacokinetics; Pharmacodynamics; In vivo residence;
Preliminary characterization of dexamethasone-loaded cross-linked hyaluronic acid films for topical ocular therapy by J.A. Calles; A. López-García; E.M. Vallés; S.D. Palma; Y. Diebold (237-243).
Display OmittedThe aim of this work was to design and characterize cross-linked hyaluronic acid (HA)–itaconic acid (IT) films loaded with dexamethasone sodium phosphate salt (DEX) for topical therapy of inflammatory ocular surface diseases. Films were chemically cross-linked with polyethylene glycol diglycidyl ether (PEGDE), then physical and mechanical characterization by stress–strain, X-ray diffraction, X-ray fluorescence spectrometry and swelling assays was conducted. A sequential in vitro therapeutic efficacy model was designed to assess changes in interleukin (IL)-6 production in an inflamed human corneal epithelial (HCE) cell line after film exposure. Changes in cell proliferation after film exposure were assessed using the alamarBlue® proliferation assay. Experimental findings showed desirable mechanical properties and in vitro efficacy to reduce cell inflammation. A moderately decreased proliferation rate was induced in HCE cells by DEX-loaded films, compared to commercial DEX eye drops. These results suggest that DEX and HA have opposite effects. The sequential in vitro therapeutic efficacy model arises as an efficient tool to study drug release from delivery systems by indirect measurement of a biological response.
Keywords: Hyaluronan; Dexamethasone; Model; Ocular; Inflammation;
Dendrosomal curcumin nanoformulation modulate apoptosis-related genes and protein expression in hepatocarcinoma cell lines by Maryam Montazeri; Majid Sadeghizadeh; Yones Pilehvar-Soltanahmadi; Faraz Zarghami; Samaneh Khodi; Mina Mohaghegh; Hadi Sadeghzadeh; Nosratollah Zarghami (244-254).
Display OmittedThe side-effects observed in conventional therapies have made them unpromising in curing Hepatocellular carcinoma; therefore, developing novel treatments can be an overwhelming significance. One of such novel agents is curcumin which can induce apoptosis in various cancerous cells, however, its poor solubility is restricted its application. To overcome this issue, this paper employed dendrosomal curcumin (DNC) was employed to in prevent hepatocarcinoma in both RNA and protein levels. Hepatocarcinoma cells, p53 wild-type HepG2 and p53 mutant Huh7, were treated with DNC and investigated for toxicity study using MTT assay. Cell cycle distribution and apoptosis were analyzed using Flow-cytometry and Annexin-V-FLUOS/PI staining. Real-time PCR and Western blot were employed to analyze p53, BAX, Bcl-2, p21 and Noxa in DNC-treated cells. DNC inhibited the growth in the form of time-dependent manner, while the carrier alone was not toxic to the cell. Flow-cytometry data showed the constant concentration of 20 μM DNC during the time significantly increases cell population in SubG1 phase. Annexin-V-PI test showed curcumin-induced apoptosis was enhanced in Huh7 as well as HepG2, compared to untreated cells. Followed by treatment, mRNA expression of p21, BAX, and Noxa increased, while the expression of Bcl-2 decreased, and unlike HepG2, Huh7 showed down-regulation of p53. In summary, DNC-treated hepatocellular carcinoma cells undergo apoptosis by changing the expression of genes involved in the apoptosis and proliferation processes. These findings suggest that DNC, as a plant-originated therapeutic agent, could be applied in cancer treatment.
Keywords: Dendrosomal curcumin; p53 mutant; Apoptosis; Hepatocarcinoma; Real-time PCR;
Hot-melt extruded filaments based on pharmaceutical grade polymers for 3D printing by fused deposition modeling by Alice Melocchi; Federico Parietti; Alessandra Maroni; Anastasia Foppoli; Andrea Gazzaniga; Lucia Zema (255-263).
Display OmittedFused deposition modeling (FDM) is a 3D printing technique based on the deposition of successive layers of thermoplastic materials following their softening/melting. Such a technique holds huge potential for the manufacturing of pharmaceutical products and is currently under extensive investigation. Challenges in this field are mainly related to the paucity of adequate filaments composed of pharmaceutical grade materials, which are needed for feeding the FDM equipment. Accordingly, a number of polymers of common use in pharmaceutical formulation were evaluated as starting materials for fabrication via hot melt extrusion of filaments suitable for FDM processes. By using a twin-screw extruder, filaments based on insoluble (ethylcellulose, Eudragit® RL), promptly soluble (polyethylene oxide, Kollicoat® IR), enteric soluble (Eudragit® L, hydroxypropyl methylcellulose acetate succinate) and swellable/erodible (hydrophilic cellulose derivatives, polyvinyl alcohol, Soluplus®) polymers were successfully produced, and the possibility of employing them for printing 600 μm thick disks was demonstrated. The behavior of disks as barriers when in contact with aqueous fluids was shown consistent with the functional application of the relevant polymeric components. The produced filaments were thus considered potentially suitable for printing capsules and coating layers for immediate or modified release, and, when loaded with active ingredients, any type of dosage forms.
Keywords: 3D printing; Fused deposition modeling; Hot melt extrusion; Filament; Pharmaceutical grade polymer; Drug delivery system;
Real-time monitoring of the mechanism of ibuprofen-cationic dextran crystanule formation using crystallization process informatics system (CryPRINS) by Amos Olusegun Abioye; George Tangyie Chi; Elena Simone; Zoltan Nagy (264-278).
Display OmittedOne step aqueous melt-crystallization and in situ granulation was utilized to produce ibuprofen-cationic dextran [diethylaminoethyl dextran (Ddex)] conjugate crystanules without the use of surfactants or organic solvents. This study investigates the mechanism of in situ granulation-induced crystanule formation using ibuprofen (Ibu) and Ddex. Laboratory scale batch aqueous crystallization system containing in situ monitoring probes for particle vision measurement (PVM), UV–vis measurement and focused beam reflectance measurements (FBRM) was adapted using pre-defined formulation and process parameters. Pure ibuprofen showed nucleation domain between 25 and 64 °C, producing minicrystals with onset of melting at 76 °C and enthalpy of fusion (ΔH) of 26.22 kJ/mol. On the other hand Ibu-Ddex crystanules showed heterogeneous nucleation which produced spherical core-shell structure. PVM images suggest that internalization of ibuprofen in Ddex corona occurred during the melting phase (before nucleation) which inhibited crystal growth inside the Ddex corona. The remarkable decrease in ΔH of the crystanules from 26.22 to 11.96 kJ/mol and the presence of broad overlapping DSC thermogram suggests formation of ibuprofen-Ddex complex and crystalline-amorphous transformation. However Raman and FTIR spectra did not show any significant chemical interaction between ibuprofen and Ddex. A significant increase in dissolution efficiency from 45 to 81% within 24 h and reduced burst release provide evidence for potential application of crystanules in controlled drug delivery systems. It was evident that in situ granulation of ibuprofen inhibited the aqueous crystallization process. It was concluded that in situ granulation-aqueous crystallization technique is a novel unit operation with potential application in continuous pharmaceutical processing.
Keywords: Aqueous crystallization; Crystal-granule conjugate; Ibuprofen crystanules; Mechanism of crystanule formation; Chord length distribution; Continuous pharmaceutical processing;
Formulation and characterization of a 0.1% rapamycin cream for the treatment of Tuberous Sclerosis Complex-related angiofibromas by Guillaume Bouguéon; Frédéric Lagarce; Ludovic Martin; Hélène Pailhoriès; Guillaume Bastiat; Sandy Vrignaud (279-284).
Display OmittedMedicines for the treatment of rare diseases frequently do not attract the interest of the pharmaceutical industry, and hospital pharmacists are thus often requested by physicians to prepare personalized medicines. Tuberous Sclerosis Complex (TSC) is a rare disease that causes disfiguring lesions named facial angiofibromas. Various topical formulations of rapamycin (=sirolimus) have been proved effective in treating these changes in small case series. The present study provides for the first time characterization of a 0.1% rapamycin cream formulation presenting good rapamycin solubilisation. The first step of the formulation is solubilisation of rapamycin in Transcutol®, and the second step is the incorporation of the mixture in an oil-in-water cream.A HPLC stability-indicating method was developed. Rapamycin concentration in the cream was tested by HPLC and confirmed that it remained above 95% of the initial concentration for at least 85 days, without characteristic degradation peaks. The preparation met European Pharmacopoeia microbial specifications throughout storage in aluminum tubes, including when patient use was simulated. Odour, appearance and colour of the preparation were assessed and no change was evidenced during storage. The rheological properties of the cream also remained stable throughout storage.To conclude, we report preparation of a novel cream formulation presenting satisfactory rapamycin solubilisation for the treatment of TSC cutaneous manifestations, with stability data. The cream is currently being used by our patients. Efficacy and tolerance will be reported later.
Keywords: Rapamycin; Sirolimus; Tuberous Sclerosis; m-Tor inhibitor; Topic formulation; Stability study;
Solid state drug-polymer miscibility studies using the model drug ABT-102 by Rajan Jog; Rajeev Gokhale; Diane J. Burgess (285-295).
Display OmittedAmorphous solid dispersions typically suffer storage stability issues due to: their amorphous nature, high drug loading, uneven drug:stabilizer ratio and plasticization effects as a result of hygroscopic excipients. An extensive solid state miscibility study was conducted to aid in understanding the mechanisms involved in drug/stabilizer interactions. ABT-102 (model drug) and nine different polymers with different molecular weights and viscosities were selected to investigate drug/polymer miscibility. Three different polymer:drug ratios (1:3, 1:1 and 3:1, w/w) were analyzed using: DSC, FTIR and PXRD. Three different techniques were used to prepare the amorphous solid dispersions: serial dilution, solvent evaporation and spray drying. Spray drying was the best method to obtain amorphous solid dispersions. However, under certain conditions amorphous formulations could be obtained using solvent evaporation. Melting point depression was used to calculate interaction parameters and free energy of mixing for the various drug polymer mixtures. The spray dried solid dispersions yielded a negative free energy of mixing which indicated strong drug-polymer miscibility compared to the solvent evaporation and serial dilution method. Soluplus was the best stabilizer compared to PVP and HPMC, which is probably a consequence of strong hydrogen bonding between the two C＝O moieties of soluplus and the drug N―H moieities.
Keywords: Amorphous solid dispersion; Spray drying; Miscibility; Solid-state; Interaction; Thermodynamics;
CTG-loaded liposomes as an approach for improving the intestinal absorption of asiaticoside in Centella Total Glucosides by Jiayu Wang; Changhua Ma; Chengjie Guo; Ruijuan Yuan; Xueyan Zhan (296-304).
Display OmittedCentella Total Glucosides (CTG),obtained from Centella asiatica (L.), have been shown to possess a multitude of pharmacological activities, however, oral administeration of CTG failed to fulfill their therapeutic potentials due to the low bioavailability. In this study, the author prepared the liposomes encapsulated CTG using the ethanol injection method in order to enhance their intestinal absorption. The average particle size and the polydispersityindex(PDI) of CTG-loaded liposome in a batch are 137.0 nm and 0.283, and the CTG-loaded amounts in CTG-loaded liposomes were 0.177 mg mL−1 and the zeta potential of CTG-loaded lipsomes is −21.2 mV. The TEM images of CTG-loaded lipsomes showed that CTG-loaded liposomes are round and maintain high structural integrity, and their DSC thermograms indicated that CTG might be incorporated into the aqueous phase of DPPC to become more stable. The everted rat gut sac model was used to study the absorption characteristic of CTG-loaded solution in rat intestines. The cumulative absorption amount (Q) and the cumulative absorption percentage (P%) of asiaticoside in the CTG-loaded liposome was significantly higher than that in CTG (P < 0.05), both the steady-state infiltration rate (Jss, μg cm−2 s−1) and the permeability coefficient (Papp, cm s−1) of asiaticoside in CTG-loaded liposomes were significantly higher than those in CTG (P < 0.05), which revealed that the liposomes encapsulated CTG can promote the absorption of asiaticoside in the ileum of the rats by enhancing its transmembrane permeability. The above study will provide the experimental evidence and a reference for the development of the oral dosage forms of Centella total glucosides.
Keywords: Centella Total Glucosides; Bioavailability; Liposomes; Everted rat gut sac model; Absorption characteristic;
Comparison of amorphous states prepared by melt-quenching and cryomilling polymorphs of carbamazepine by Yannick Guinet; Laurent Paccou; Florence Danède; Jean-François Willart; Patrick Derollez; Alain Hédoux (305-313).
Display OmittedThe physical state of amorphous powder obtained by cryomilling forms I and III of carbamazepine (CBZ) were analyzed from low-wavenumber Raman spectroscopy investigations and compared to that of the quenched liquid. This analysis has shown subtle structural modifications between the amorphous states prepared by melt-quenching and cryomilling polymorphs I and III of CBZ. Moreover, two different non-isothermal crystallization mechanisms from these two different types of amorphous states were revealed, in agreement with calorimetric analyzes. Raman spectroscopy and differential scanning calorimetry experiments performed on cryomilled forms I and III of CBZ, provide information on the bimodal crystallization, observed upon heating several amorphous organic crystalline materials produced by milling. This study clearly shows that milling gives the opportunity to explore new amorphous states which cannot be achieved using the classical melt-quenching method.
Keywords: Physical state; Amorphous; Low-wavenumber raman spectroscopy; Cryomilling; Crystallization;
Synthesis and characterization of a PAMAM-OH derivative containing an acid-labile β-thiopropionate bond for gene delivery by Kang Chen; Qing Chen; Kuanglei Wang; Jia Zhu; Weinan Li; Wenpan Li; Lipeng Qiu; Guannan Guan; Mingxi Qiao; Xiuli Zhao; Haiyang Hu; Dawei Chen (314-327).
Display OmittedThe present report describes the synthesis of a hydroxyl terminal PAMAM dendrimer (PAMAM-OH) derivative (PAMSPF). The hydroxyls of PAMAM-OH were attached to S-Methyl-l-cysteine (SMLC) via an acid-labile ester bond, named as β-thiopropionate bond, followed by modification with folic acid (FA) through a polyethylene glycol (PEG) linker. The degrees of attachment of SMLC and FA to the PAMAM-OH backbone were 83.9% and 12.8%, respectively. PAMSPF could condense DNA to form spherical nanoparticles with particle sizes of ∼200 nm and remain stable in the presence of heparin and nuclease. The β-thiopropionate bond in PAMSPF was hydrolyzed completely and the DNA release rate was 95.8 ± 3.3% after incubation under mildly acidic conditions at 37 °C for 3 h. PAMSPF/DNA was less cytotoxic to KB and HepG2 cells and exhibited a higher gene transfection efficiency than native PAMAM/DNA. The uptake assays showed that PAMSPF/DNA entered KB cells within 0.5 h through folate receptor-mediated endocytosis and escaped from endosomes within 2 h. In addition, PAMSPF/DNA displayed long circulation time along with excellent targeting of tumor sites in vivo. These findings demonstrate that PAMSPF is an excellent carrier for safe and effective gene delivery.
Keywords: PAMAM-OH; β-thiopropionate; Acid-labile polymer; Gene delivery; Transfection; Cytotoxicity;
Sustained-release microsphere formulation containing an agrochemical by polyurethane polymerization during an agitation granulation process by Takatoshi Terada; Manabu Tagami; Toshiro Ohtsubo; Yasunori Iwao; Shuji Noguchi; Shigeru Itai (328-337).
Display OmittedIn this report, a new solventless microencapsulation method by synthesizing polyurethane (PU) from polyol and isocyanate during an agglomeration process in a high-speed mixing apparatus was developed. Clothianidin (CTD), which is a neonicotinoid insecticide and highly effective against a wide variety of insect pests, was used as the model compound. The microencapsulated samples covered with PU (CTD microspheres) had a median diameter of <75 μm and sustained-release properties. The CTD microspheres were analyzed by synchrotron X-ray computed tomography measurements. Multiple cores of CTD and other solid excipient were dispersed in PU. Although voids appeared in the CTD microspheres after CTD release, the spherical shape of the microspheres remained stable and no change in its framework was observed. The experimental release data were highly consistent with the Baker–Lonsdale model derived from drug release of spherical monolithic dispersions and consistent with the computed tomography measurements.
Keywords: Sustained release; Agrochemical; Polyurethane; Microsphere; Agitation granulation;
Ternary inclusion complex formation and stabilization of limaprost, a prostaglandin E1 derivative, in the presence of α- and β-cyclodextrins in the solid state by Yasuo Inoue; Daisuke Iohara; Noboru Sekiya; Masanobu Yamamoto; Hiroyuki Ishida; Yoko Sakiyama; Fumitoshi Hirayama; Hidetoshi Arima; Kaneto Uekama (338-347).
Display OmittedLimaprost/α-cyclodextrin (CD)/β-CD ternary inclusion complex was prepared by freeze-drying a solution containing all three components. Under humid conditions, limaprost was more stable in the ternary α-/β-CD inclusion complex than in the binary α- or β-CD complex. Specifically, during storage at 30 °C/75% relative humidity (R.H.) for 4 weeks, about 19% of limaprost degraded into 17S,20-dimethyl-trans-Δ2-prostaglandin A1 (referred as 11-deoxy-Δ10) in the β-CD complex, 8.1% degraded in the α-CD complex, and only 2.2% degraded in the α-/β-CD complex. The mechanism of limaprost stabilization in the presence of both CDs was investigated by Raman and solid-state NMR spectroscopy and powder X-ray diffractometry. The fast degradation of limaprost to 11-deoxy-Δ10 in the β-CD complex was due to the rapid crystallization of β-CD from the complex, liberating the free amorphous drug, which is susceptible to degradation. The dissociation and crystallization of β-CD from the inclusion complex were suppressed by freeze-drying limaprost in the presence of both α- and β-CDs. In addition, the interaction between limaprost and the two CDs was reinforced by inclusion of different moieties of limaprost: α-CD predominantly included the alkyl ω-chain, whereas β-CD included the five-membered ring. Thus, a stable ternary inclusion complex was formed that included limaprost, maintaining the amorphous state of the complex and dramatically stabilizing the drug under humid conditions.
Keywords: Cyclodextrin; Limaprost; Ternary inclusion complex; Stability; Solid state;
A dual pH/Redox responsive copper-ligand nanoliposome bioactive complex for the treatment of chronic inflammation by Simphiwe Mavuso; Yahya E. Choonara; Thashree Marimuthu; Pradeep Kumar; Lisa C. du Toit; Pierre P.D. Kondiah; Viness Pillay (348-359).
Display OmittedA novel dual pH/redox-responsive polymeric nanoliposome system (NLs) loaded with a copper-liganded bioactive complex was prepared and designed as a controlled delivery system for the management of inflammation. The NLs were synthesised after preparation of the copper-glyglycine-prednisolone succinate] ([(Cu(glygly)(PS)]) complex, and the dual pH/redox responsive biopolymer respectively. The methodology undertaken for the development of the drug delivery system involved coordination of the bioactive to Copper (II), preparation of dual pH/redox responsive biopolymer, and the synthesis of dual pH/redox nanoliposomes. Characterisations of the prepared copper-liganded bioactive [Copper-glyglycine-prednisolone succinate] ([(Cu(glygly)(PS)]) complex, dual pH/redox responsive biopolymer (Eudragit E100-cystamine) and [(Cu(glygly)(PS)]-loaded NLs were carried out using spectroscopic and physicochemical techniques. Results indicated a high inflammatory/oxidant inhibitory activity of [Cu(glygly)(PS)] in comparison to the free PS drug. The [Cu(glygly)(PS)] complex exhibited a significant free radical-scavenging activity (60.1 ± 1.2%) and lipoxygenase (LOX-5) inhibitory activity (36.6 ± 1.3%) in comparison to PS which resulted in activity of 4.4 ± 1.4% and inhibition of 6.1 ± 2.6% respectively. The [Cu(glygly)(PS)] loaded NLs demonstrated low release profiles of 22.9 ± 5.4% in 6 h at pH 7.4, in comparison to a significant accelerated release at pH 5 in a reducing environment of 75.9 ± 3.7% over 6 h duration. Results suggest that the novel copper-liganded bioactive delivery system with controlled drug release mechanism could serve as a potential drug delivery system candidate in the management of inflammation.
Keywords: Inflammation; Dual pH/redox responsive; Nanoliposomes; Copper-glyglycine-prednisolone succinate;
Thiolated graphene oxide as promising mucoadhesive carrier for hydrophobic drugs by Irene Pereira de Sousa; Katrin Buttenhauser; Wongsakorn Suchaoin; Alexandra Partenhauser; Mara Perrone; Barbara Matuszczak; Andreas Bernkop-Schnürch (360-367).
Display OmittedThe aim of this study was to improve the mucoadhesive properties of graphene by conjugating thiol ligands, in order to formulate an oral delivery system for hydrophobic drugs showing long mucus residence time.Graphene oxide was obtained by oxidation of graphite and then was thiolated following two synthetic paths. On the one hand, the hydroxyl groups were conjugated with thiourea passing through the formation of a brominated intermediate. On the other hand, the carboxylic acid groups were conjugated with cysteamine via carbodiimide chemistry. The mucoadhesive properties of thiolated graphene were evaluated by rheological measurements and by residence time assay. Then, valsartan was loaded on thiolated graphene and the release profile was evaluated in simulated intestinal fluid.Following both synthetic paths it was possible to obtain thiolated graphene bearing 215–302 μmol SH/g product. Both products induced after 1 h incubation an increase of mucus viscosity of about 22–33-fold compared to unmodified graphite. The residence time assay confirmed that 60% of thiolated graphene could be retained on intestinal mucosa after 4 h incubation, whereas just 20% of unmodified graphite could be retained. Valsartan could be loaded with a drug loading of about 31 ± 0.3% and a sustained release profile was observed for both formulations.According to the presented data, the thiolation of graphene could improve its mucoadhesive properties. Therefore, thiolated graphene represents a promising platform for oral delivery of hydrophobic drugs, possessing a long residence time on intestinal mucosa which allows the release of the loaded drug close to the adsorptive epithelium.
Keywords: Mucoadhesion; Graphene; Graphene oxide; Thiolation; Biological barrier; Valsartan;
Effect of co-solutes and process variables on crystallinity and the crystal form of freeze-dried myo-inositol by Ken-ichi Izutsu; Riho Kusano; Ryoko Arai; Hiroyuki Yoshida; Masataka Ito; Hiroko Shibata; Kiyohiko Sugano; Yukihiro Goda; Katsuhide Terada (368-374).
Display OmittedThe purpose of this study was to elucidate how co-solutes affect the crystallization of small solute molecules during freeze-drying and subsequent storage. Crystallization profiles of myo-inositol and its mixture with dextran 40k in frozen solutions and dried solids were assessed by thermal analysis (DSC), powder-X-ray diffraction, and simultaneous DSC and PXRD analysis. Higher mass ratios of dextran maintained myo-inositol in the non-crystalline mixture state, in frozen solutions, during freeze-drying process, and exposure of dried solids to higher temperatures. Co-lyophilization with a lower mass ratio of dextran resulted in solids containing a variety of myo-inositol crystal forms and crystallinity depending on the composition and thermal history of the process. Heating of some inositol-rich amorphous solids showed crystallization of myo-inositol in the metastable form and its transition to stable form before melting. Heat-treatment of inositol-rich frozen solutions resulted in high crystallinity stable-form inositol solids, leaving dextran in the amorphous state. Sufficient direct molecular interactions (e.g., hydrogen bonding) should explain the stability of dextran-rich amorphous solids. Optimizing solute composition and processes should be a potent way to control crystal form and crystallinity of components in freeze-dried formulations.
Keywords: Freeze-drying; Crystallization; Crystallinity; Crystal form; Co-lyophilization; Myo-inositol; Polymorph;
Design and optimization of novel paclitaxel-loaded folate-conjugated amphiphilic cyclodextrin nanoparticles by Nazlı Erdoğar; Güneş Esendağlı; Thorbjorn T. Nielsen; Murat Şen; Levent Öner; Erem Bilensoy (375-390).
Display OmittedThe new folate-targeted amphiphilic cyclodextrin nanoparticles carrying chemotherapeutic drug PCX to breast tumors result in higher anticancer efficacy with reduced side effects and equivalent efficacy capable of cellular internalization with a folate dependent mechanism.As nanomedicines are gaining momentum in the therapy of cancer, new biomaterials emerge as alternative platforms for the delivery of anticancer drugs with bioavailability problems. In this study, two novel amphiphilic cyclodextrins (FCD-1 and FCD-2) conjugated with folate group to enable active targeting to folate positive breast tumors were introduced. The objective of this study was to develop and characterize new folated-CD nanoparticles via 32 factorial design for optimal final parameters. Full physicochemical characterization studies were performed. Blank and paclitaxel loaded FCD-1 and FCD-2 nanoparticles remained within the range of 70–275 nm and 125–185 nm, respectively. Zeta potential values were neutral and −20 mV for FCD-1 and FCD-2 nanoparticles, respectively. Drug release studies showed initial burst release followed by a longer sustained release. Blank nanoparticles had no cytotoxicity against L929 cells. T-47D and ZR-75-1 human breast cancer cells with different levels of folate receptor expression were used to assess anti-cancer efficacy. Through targeting the folate receptor, these nanoparticles were efficiently engulfed by the breast cancer cells. Additionally, breast cancer cells became more sensitive to cytotoxic and/or cytostatic effects of PCX delivered by FCD-1 and FCD-2. In conclusion, these novel folate-conjugated cyclodextrin nanoparticles can therefore be considered as promising alternative systems for safe and effective delivery of paclitaxel with a folate-dependent mechanism.
Keywords: Nanoparticle; Factorial design; Active targeting; Amphiphilic cyclodextrin; Paclitaxel; Cancer;
Resveratrol cocrystals with enhanced solubility and tabletability by Zhengzheng Zhou; Wanying Li; Wei-Jhe Sun; Tongbu Lu; Henry H.Y. Tong; Changquan Calvin Sun; Ying Zheng (391-399).
Display OmittedTwo new 1:1 cocrystals of resveratrol (RES) with 4-aminobenzamide (RES-4ABZ) and isoniazid (RES-ISN) were synthesized by liquid assisted grinding (LAG) and rapid solvent removal (RSR) methods using ethanol as solvent. Their physiochemical properties were characterized using PXRD, DSC, solid state and solution NMR, FT-IR, and HPLC. Pharmaceutically relevant properties, including tabletability, solubility, intrinsic dissolution rate, and hygroscopicity, were evaluated. Temperature-composition phase diagram for RES-ISN cocrystal system was constructed from DSC data. Both cocrystals show higher solubility than resveratrol over a broad range of pH. They are phase stable and non-hygroscopic even under high humidity conditions. Importantly, both cocrystals exhibit improved solubility and tabletability compared with RES, which make them more suitable candidates for tablet formulation development.
Keywords: Resveratrol (RES); Cocrystal; Solubility; Tabletability; Mechanical property;
Introducing a highly dispersed reduced graphene oxide nano-biohybrid employing chitosan/hydroxyethyl cellulose for controlled drug delivery by Hanieh Mianehrow; Ronak Afshari; Saeedeh Mazinani; Farhad Sharif; Majid Abdouss (400-407).
Display OmittedIn this research, an attempt was made to stabilize reduced graphene oxide (rGO) in all pH ranges, incorporating both chitosan (CS) and hydroxyethyl cellulose (HEC) to make a proper drug carrier with suitable stability and drug release behaviour. The stability of rGO-CS-HEC nanohybrid was assessed using field emission scanning electron microscopy (FE-SEM), ultraviolet-visible spectroscopy (UV–Vis) and Zeta potential measurements. Results depicted that the novel synthesized nanohybrid was stable in all pH ranges, due to the utilization of HEC, while without incorporation of this material, the rGO-CS nanohybrid aggregated at neutral and alkaline media, due to the ionic nature of chitosan. In addition, drug loading and release behaviour of folic acid (FA), as a model drug, was investigated to assess the role of chitosan on the release behaviour of FA from the rGO-CS-HEC nanohybrid in comparison with rGO-HEC and rGO-CS nanohybrids. It was proved that the resultant nanohybrid could release nearly 27% more FA than the rGO-HEC nanohybrid and only 9% lower than the rGO-CS nanohybrid during 120 h. Moreover, the biocompatibility of the resultant nanohybrid was also checked to introduce the novel rGO-CS-HEC nanohybrid as a suitable candidate for drug delivery application.
Keywords: Nano-biohybrid; Reduced graphene oxide; Chitosan; Hydroxyethyl cellulose; Stabilization; Drug delivery application;
Targeted chitosan-based bionanocomposites for controlled oral mucosal delivery of chlorhexidine by Renée Onnainty; Barbara Onida; Paulina Páez; Marcela Longhi; Antonello Barresi; Gladys Granero (408-418).
Display OmittedThe purpose of this study was to develop sustained release systems based on chitosan (CS) and montmorillonite (MMT) for chlorhexidine (CLX). Nanocomposites were prepared by ion-exchange. CLX systems were characterized by X-ray powder diffraction (XRD), thermal analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray fluorescence analysis (XRF). The mucoadhesion properties of CLX nanocomposites were evaluated by SEM. The release behavior of these systems was also studied by the dialysis technique. The antibacterial activity was investigated in vitro by the disk diffusion test. Results showed long-term sustained release of CLX from the hybrid carriers without initial burst release. The release profiles of CLX from the carriers suggested the diffusion through a swollen matrix and water filled pores as the controlled drug release mechanism. The CLX hybrid nanosystem containing the positively-charged chitosan exhibited good mucoadhesion properties maintaining the CLX antimicrobial properties.
Keywords: Chlorhexidine; Chitosan; Nanocomposites; Drug delivery systems; Mucoadhesion; Antibacterial activity;
Comparison of the cohesion-adhesion balance approach to colloidal probe atomic force microscopy and the measurement of Hansen partial solubility parameters by inverse gas chromatography for the prediction of dry powder inhalation performance by Matthew D. Jones; Graham Buckton (419-430).
Display OmittedThe abilities of the cohesive-adhesive balance approach to atomic force microscopy (AFM) and the measurement of Hansen partial solubility parameters by inverse gas chromatography (IGC) to predict the performance of carrier-based dry powder inhaler (DPI) formulations were compared. Five model drugs (beclometasone dipropionate, budesonide, salbutamol sulphate, terbutaline sulphate and triamcinolone acetonide) and three model carriers (erythritol, α-lactose monohydrate and d-mannitol) were chosen, giving fifteen drug-carrier combinations. Comparison of the AFM and IGC interparticulate adhesion data suggested that they did not produce equivalent results. Comparison of the AFM data with the in vitro fine particle delivery of appropriate DPI formulations normalised to account for particle size differences revealed a previously observed pattern for the AFM measurements, with a slightly cohesive AFM CAB ratio being associated with the highest fine particle fraction. However, no consistent relationship between formulation performance and the IGC data was observed. The results as a whole highlight the complexity of the many interacting variables that can affect the behaviour of DPIs and suggest that the prediction of their performance from a single measurement is unlikely to be successful in every case.
Keywords: Adhesion; Atomic force microscopy; Dry powder inhaler (DPI); Inverse gas chromatography; Materials science; Physical characterisation;
How do the physicochemical properties of nanoliposomes affect their interactions with the hCMEC/D3 cellular model of the BBB? by Konstantina Papadia; Eleni Markoutsa; Sophia G. Antimisiaris (431-438).
Display OmittedNanosized liposomes composed of 1,2-distearoyl-sn-glycerol-3-phosphatidylcholine (DSPC), cholesterol and polyethylene glycol-conjugated phospholipid (PEG), incorporating FITC-dextran (FITC) and in some cases also Rhodamine-conjugated phospholipid (RHO) (as labels) were constructed by the thin film hydration method, followed by extrusion; membranes with pore diameters from 50 to 400 nm were used, while charged vesicles were produced by partially replacing DSPC with 1,2-distearoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (DSPG). The uptake of liposomes by hCMED/D3 cells was evaluated by measuring FITC in cells, and their permeability across cell monolayers was evaluated, by measuring the FI of liposome associated-FITC and RHO in the receiving side of a monolayer-transwell system. Results prove that liposome size has a significant effect on their uptake and permeability (for both charged and non-charged vesicles). The effect of liposome charge on cell uptake was slight (but significant), however charge (in the range from −2 to −16 mV) did not significantly affect vesicle permeability; a significant decrease was only demonstrated for the liposome with the highest charge.
Keywords: Liposomes; Nanoparticle; Cell model; BBB; Size; Charge; Permeability; Uptake; hCMEC/D3;
Noninvasive porosity measurement of biconvex tablets using terahertz pulses by Prince Bawuah; Tuomas Ervasti; Nicholas Tan; J. Axel Zeitler; Jarkko Ketolainen; Kai-Erik Peiponen (439-443).
Display OmittedBiconvex pharmaceutical microcrystalline cellulose (MCC) compacts were investigated by the detection of terahertz (THz) pulse delay in the transmission measurement mode. The dimensions of the tablets were kept as constants but the porosity was a priori known variable. It is shown that the porosity of the biconvex compact has a linear correlation with the THz pulse delay. By constructing a calibration line between these two parameters (i.e. porosity and THz pulse delay), it is possible to non-invasively detect porosity of biconvex tablets. We suggest that this preliminary study could be the starting point of in-depth future studies on the screening of porosity and related properties of real biconvex pharmaceutical tablets using terahertz sensing techniques.
Keywords: Biconvex pharmaceutical compact; Microcrystalline cellulose; Porosity; Terahertz pulse delay;
Determination of the mechanical properties of solid and cellular polymeric dosage forms by diametral compression by Aron H. Blaesi; Nannaji Saka (444-453).
In this study, a theory is first developed to extract the relevant mechanical properties of ducticle and cellular dosage forms from diametral compression tests. Experiments are then conducted to derive the elastic modulus and yield strength of both solid and cellular polymeric dosage forms.Display OmittedAt present, the immediate-release solid dosage forms, such as the oral tablets and capsules, are granular solids. They release drug rapidly and have adequate mechanical properties, but their manufacture is fraught with difficulties inherent in processing particulate matter. Such difficulties, however, could be overcome by liquid-based processing. Therefore, we have recently introduced polymeric cellular (i.e., highly porous) dosage forms prepared from a melt process. Experiments have shown that upon immersion in a dissolution medium, the cellular dosage forms with polyethylene glycol (PEG) as excipient and with predominantly open-cell topology disintegrate by exfoliation, thus enabling rapid drug release. If the volume fraction of voids of the open-cell structures is too large, however, their mechanical strength is adversely affected. At present, the common method for determining the tensile strength of brittle, solid dosage forms (such as select granular forms) is the diametral compression test. In this study, the theory of diametral compression is first refined to demonstrate that the relevant mechanical properties of ductile and cellular solids (i.e., the elastic modulus and the yield strength) can also be extracted from this test. Diametral compression experiments are then conducted on PEG-based solid and cellular dosage forms. It is found that the elastic modulus and yield strength of the open-cell structures are about an order of magnitude smaller than those of the non-porous solids, but still are substantially greater than the stiffness and strength requirements for handling the dosage forms manually. This work thus demonstrates that melt-processed polymeric cellular dosage forms that release drug rapidly can be designed and manufactured to have adequate mechanical properties.
Keywords: Diametral compression test; Mechanical properties of pharmaceutical tablets; Cellular dosage forms; Cellular materials; Drug manufacture; Mechanical characterization of cellular solids;
Solvent database and in silico classification: A new methodology for solvent substitution and its application for microencapsulation process by Amélie Levet; Claire Bordes; Yohann Clément; Pierre Mignon; Henry Chermette; Valérian Forquet; Christophe Morell; Pierre Lantéri (454-464).
Development of gellan gum containing formulations for transdermal drug delivery: Component evaluation and controlled drug release using temperature responsive nanogels by Carlos A. Carmona-Moran; Oleksandra Zavgorodnya; Andrew D. Penman; Eugenia Kharlampieva; S. Louis Bridges; Robert W. Hergenrother; Jasvinder A. Singh; Timothy M. Wick (465-476).
Display OmittedEnhancing skin permeation is important for development of new transdermal drug delivery formulations. This is particularly relevant for non-steroidal anti-inflammatory drugs (NSAIDs). To address this, semisolid gel and solid hydrogel film formulations containing gellan gum as a gelling agent were developed and the effects of penetration enhancers (dimethyl sulfoxide, isopropyl alcohol and propylene glycol) on transport of the NSAID diclofenac sodium was quantified. A transwell diffusion system was used to accelerate formulation development. After 4 h, diclofenac flux from a superior formulation of the semisolid gel or the solid hydrogel film was 130 ± 11 μg/cm2 h and 108 ± 7 μg/cm2 h, respectively, and significantly greater than that measured for a currently available diclofenac sodium topical gel (30 ± 4 μg/cm2 h, p < 0.05) or solution formulation (44 ± 6 μg/cm2 h, p< 0.05) under identical conditions. Over 24 h diclofenac transport from the solid hydrogel film was greater than that measured for any new or commercial diclofenac formulation. Entrapment of temperature-responsive nanogels within the solid hydrogel film provides temperature-activated prolonged release of diclofenac. Diclofenac transport was minimal at 22 °C, when diclofenac is entrapped within temperature-responsive nanogels incorporated into the solid hydrogel film, but increased 6-fold when the temperature was increased to skin surface temperature of 32 °C. These results demonstrate the feasibility of the semisolid gel and solid hydrogel film formulations that can include thermo-responsive nanogels for development of transdermal drug formulations with adjustable drug transport kinetics.
Keywords: Transdermal drug transport; Transdermal formulation development; Diclofenac; Semisolid gel; Hydrogel film; Nanogels; Synthetic membrane;
A three-dimensional semi-analytical solution for predicting drug release through the orifice of a spherical device by Laurent Simon; Juan Ospina (477-482).
Display OmittedThree-dimensional solute transport was investigated for a spherical device with a release hole. The governing equation was derived using the Fick’s second law. A mixed Neumann-Dirichlet condition was imposed at the boundary to represent diffusion through a small region on the surface of the device. The cumulative percentage of drug released was calculated in the Laplace domain and represented by the first term of an infinite series of Legendre and modified Bessel functions of the first kind. Application of the Zakian algorithm yielded the time-domain closed-form expression. The first-order solution closely matched a numerical solution generated by Mathematica®. The proposed method allowed computation of the characteristic time. A larger surface pore resulted in a smaller effective time constant. The agreement between the numerical solution and the semi-analytical method improved noticeably as the size of the orifice increased. It took four time constants for the device to release approximately ninety-eight of its drug content.
Keywords: Spherical device; Effective time constant; Controlled release; Laplace transform;
Cholesterol-modified poly(lactide-co-glycolide) nanoparticles for tumor-targeted drug delivery by Jeong-Jun Lee; Song Yi Lee; Ju-Hwan Park; Dae-Duk Kim; Hyun-Jong Cho (483-491).
Display OmittedPoly(lactide-co-glycolide)-cholesterol (PLGA-C)-based nanoparticles (NPs) were developed for the tumor-targeted delivery of curcumin (CUR). PLGA-C/CUR NPs with ∼200 nm mean diameter, narrow size distribution, and neutral zeta potential were fabricated by a modified emulsification-solvent evaporation method. The existence of cholesterol moiety in PLGA-C copolymer was confirmed by proton nuclear magnetic resonance (1H NMR) analysis. In vitro stability of developed NPs after 24 h incubation was confirmed in phosphate buffered saline (PBS) and serum media. Sustained (∼6 days) and pH-responsive drug release profiles from PLGA-C NPs were presented. Blank PLGA and PLGA-C NPs exhibited a negligible cytotoxicity in Hep-2 (human laryngeal carcinoma) cells in the tested concentration range. According to the results of flow cytometry and confocal laser scanning microscopy (CLSM) studies, PLGA-C NPs presented an improved cellular accumulation efficiency, compared to PLGA NPs, in Hep-2 cells. Enhanced in vivo tumor targetability of PLGA-C NPs, compared to PLGA NPs, in Hep-2 tumor-xenografted mouse model was also verified by a real-time near-infrared fluorescence (NIRF) imaging study. Developed PLGA-C NPs may be a candidate of efficient and biocompatible nanosystems for tumor-targeted drug delivery and cancer imaging.
Keywords: Cancer; Cholesterol; Curcumin; Endocytosis; Nanoparticle;
Emerging technology: A key enabler for modernizing pharmaceutical manufacturing and advancing product quality by Thomas F. O’Connor; Lawrence X. Yu; Sau L. Lee (492-498).
Issues in product quality have produced recalls and caused drug shortages in United States (U.S.) in the past few years. These quality issues were often due to outdated manufacturing technologies and equipment as well as lack of an effective quality management system. To ensure consistent supply of safe, effective and high-quality drug products available to the patients, the U.S. Food and Drug Administration (FDA) supports modernizing pharmaceutical manufacturing for improvements in product quality. Specifically, five new initiatives are proposed here to achieve this goal. They include: (i) advancing regulatory science for pharmaceutical manufacturing; (ii) establishing a public-private institute for pharmaceutical manufacturing innovation; (iii) creating incentives for investment in the technological upgrade of manufacturing processes and facilities; (iv) leveraging external expertise for regulatory quality assessment of emerging technologies; and (v) promoting the international harmonization of approaches for expediting the global adoption of emerging technologies.
Keywords: Pharmaceutical manufacturing; Product quality; Emerging technologies; Innovation; Regulatory science;
Apomorphine and its esters: Differences in Caco-2 cell permeability and chylomicron affinity by Nrupa Borkar; Zhizhong Chen; Lasse Saaby; Anette Müllertz; Anders E. Håkansson; Christian Schönbeck; Mingshi Yang; René Holm; Huiling Mu (499-506).
Schematic representation of transport of apomorphine and its esters across Caco-2 cell monolayer.Display OmittedOral delivery of apomorphine via prodrug principle may be a potential treatment for Parkinson’s disease. The purpose of this study was to investigate the transport and stability of apomorphine and its esters across Caco-2 cell monolayer and their affinity towards chylomicrons. Apomorphine, monolauroyl apomorphine (MLA) and dilauroyl apomorphine (DLA) were subjected to apical to basolateral (A-B) and basolateral to apical (B-A) transport across Caco-2 cell monolayer. The stability of these compounds was also assessed by incubation at intestinal pH and physiological pH with and without Caco-2 cells. Molecular dynamics (MD) simulations were performed to understand the stability of the esters on a molecular level. The affinity of the compounds towards plasma derived chylomicrons was assessed. The A-B transport of intact DLA was about 150 times lower than the transport of apomorphine. In contrast, MLA was highly unstable in the aqueous media leading to apomorphine appearance basolaterally. MD simulations possibly explained the differences in hydrolysis susceptibilities of DLA and MLA. The affinity of apomorphine diesters towards plasma derived chylomicrons provided an understanding of their potential lymphatic transport. The intact DLA transport is not favorable; therefore, the conversion of DLA to MLA is an important step for intestinal apomorphine absorption.
Keywords: Caco-2; Permeability; Stability; Apomorphine; Ester prodrug; Chylomicron affinity;
Argpyrimidine-tagged rutin-encapsulated biocompatible (ethylene glycol dimers) nanoparticles: Synthesis, characterization and evaluation for targeted drug delivery by Abhishek Bhattacherjee; Kaliprasanna Dhara; Abhay Sankar Chakraborti (507-517).
Display OmittedDiabetes mellitus represents a major metabolic disorder affecting millions of people all over the world. Currently available therapeutic treatments are not good enough to control the long-term complications of diabetes. Active targeting via inclusion of a specific ligand on the nanoparticles provides effective therapeutic approach in different diseases. However, such specific drug delivery systems have not been explored much in diabetes due to lack of suitable biological targets in this disorder. Our objective is to synthesize a ligand-tagged drug-loaded nanoparticle for delivery of the drug at specific sites to enhance its therapeutic efficiency in diabetic condition. The nanoparticles have been prepared by using biocompatible ethylene glycol-bis (succinic acid N-hydroxysuccinimide ester) dimers. Although advanced glycation end products (AGEs) are the root causes of diabetic complications, argpyrimidine, an AGE, possesses antioxidant and reducing activities. AGE interacts selectively with its cell surface receptors (RAGE), which are significantly increased in diabetic condition. We have selected RAGE as the target of argpyrimidine, which is tagged on the nanoparticles as a ligand. Rutin, having anti-hyperglycemic and anti-glycating activities, has been used for nanoencapsulation. Rutin-loaded argpyrimidine-tagged nanoparticles have been synthesized and characterized. We have demonstrated the drug releasing capacity and target specificity of the synthesised drug delivery system under ex vivo and in vivo conditions.
Keywords: Diabetes mellitus; Nanotechnology; Drug delivery; Advanced glycation end product; Argpyrimidine; Rutin;
Printing medicines as orodispersible dosage forms: Effect of substrate on the printed micro-structure by C. Planchette; H. Pichler; M. Wimmer-Teubenbacher; M. Gruber; H. Gruber-Woelfler; S. Mohr; C. Tetyczka; W.-K. Hsiao; A. Paudel; E. Roblegg; J. Khinast (518-527).
Display OmittedWe present our recent advancements in developing a viable manufacturing process for printed medicine. Our approach involves using a non-contact printing system that incorporates both piezoelectric- and solenoid valve-based inkjet printing technologies, to deliver both active and inactive pharmaceutical materials onto medical-graded orodispersible films. By using two complimentary inkjet technologies, we were able to dispense an extensive range of fluids, from aqueous drug solutions to viscous polymer coating materials. Essentially, we demonstrate printing of a wide range of formulations for patient-ready, orodispersible drug dosage forms, without the risk of drug degradation by ink heating and of substrate damages (by contact printing). In addition, our printing process has been optimized to ensure that the drug doses can be loaded onto the orally dissolvable films without introducing defects, such as holes or tears, while retaining a smooth surface texture that promotes patient adherence and allows for uniform post-coatings. Results show that our platform technology can address key issues in manufacturing orodispersible drug dosage forms and bring us closer to delivering personalized and precision medicine to targeted patient populations.
Keywords: Printed medicine; Personalized medicine; Precision medicine; Orodispersible dosage form; Ink formulation; Nanosuspension; Coating; Doses combination; Pediatric; Geriatric; Patient adherence; Inkjet printing;
Corrigendum to “Topical delivery of aqueous micellar Resolvin E1 analog (RX-10045)” [Int. J. Pharm. 498 (2016) 326–334] by Kishore Cholkar; Brian C. Gilger; Ashim K. Mitra (528).