International Journal of Pharmaceutics (v.498, #1-2)

Laser-triggered intraocular implant to induce photodynamic therapy for posterior capsule opacification prevention by Zhaoguo Zhang; Wenyong Huang; Ming Lei; Yuanfeng He; Mina Yan; Xuefei Zhang; Chunshun Zhao (1-11).
Display OmittedPosterior capsule opacification (PCO) is one of the main reasons for loss of vision again after cataract surgery. In this study, intraocular lenses were modified with indocyanine green (ICG) and sealed up with PLGA to form long-term intraocular implants (ICG-IOL). When triggered by laser, ICG-IOL would induce photodynamic therapy (PDT). In-vitro cell viability assay and scratch wound healing assay demonstrated that ICG-IOL could effectively inhibit HLEpiC proliferation and migration without causing damage to the cells far away from it. Laser attenuation test indicated that ICG-IOL could be applied in vivo. In-vivo pharmacodynamics and safety study showed that ICG-IOL could significantly prevent the occurrence of PCO and was safe for intraocular normal tissue. All these results suggested that ICG-IOL would be a very promising candidate for PCO prevention.
Keywords: Laser-triggered; Intraocular implant; Indocyanine green; Photodynamic therapy; Posterior capsule opacification;

Nanoemulsion formulations for anti-cancer agent piplartine—Characterization, toxicological, pharmacokinetics and efficacy studies by Neel M. Fofaria; Hussaini Syed Sha Qhattal; Xinli Liu; Sanjay K. Srivastava (12-22).
Display OmittedPiplartine (PL) is an alkaloid found in black-pepper and known for its anticancer activity, however, due to poor solubility and lack of proper formulation, its use for oral administration is a challenge. The objective of this study was to formulate PL into nanoemulsion drug delivery system for oral delivery and thereafter evaluate toxicity, pharmacokinetics and therapeutic efficacy. Optimized nanoemulsions were formulated by self-emulsification as well as by homogenization–sonication method. Two nanoemulsions enhanced the solubility of PL with low polydispersity index and high stability. Both PL loaded nanoemulsions exhibited enhanced dissolution, cellular permeability and cytotoxic effects as compared to pure PL. Formulation of PL into nanoemulsions did not obstruct its cellular uptake in cancer cells. Blank or PL loaded nanoemulsions did not exhibited toxicity in mice upon daily oral administration for 60 days. Pharmacokinetics of PL followed a two-compartment model after intravenous administration. PL loaded nanoemulsions showed 1.5-fold increase in oral bioavailability as compared to free PL. Finally, PL loaded nanoemulsions showed marked anti-tumor activity at a dose of 10 mg/kg in melanoma tumor bearing mice. In conclusion, for the first time we have developed a stable nanoemulsion delivery system for oral administration of PL, which enhanced its solubility, oral bioavailability and anti-tumor efficacy.
Keywords: Piplartine; Piperlongumine; Nanoemulsions; Formulation experimental design; Anti-tumor activity;

Synergistic interactions between doxycycline and terpenic components of essential oils encapsulated within lipid nanocapsules against gram negative bacteria by C. Valcourt; P. Saulnier; A. Umerska; M.P. Zanelli; A. Montagu; E. Rossines; M.L. Joly-Guillou (23-31).
Display OmittedThe combination of essential oils (EOs) with antibiotics provides a promising strategy towards combating resistant bacteria. We have selected a mixture of 3 major components extracted from EOs: carvacrol (oregano oil), eugenol (clove oil) and cinnamaldehyde (cinnamon oil). These compounds were successfully encapsulated within lipid nanocapsules (LNCs). The EOs-loaded LNCs were characterised by a noticeably high drug loading of 20% and a very small particle diameter of 114 nm. The in vitro interactions between EOs-loaded LNCs and doxycycline were examined via checkerboard titration and time-kill assay against 5 Gram-negative strains: Acinetobacter baumannii SAN, A. baumannii RCH, Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa. No growth inhibition interactions were found between EOs-loaded LNCs and doxycycline (FIC index between 0.7 and 1.30). However, when bactericidal effects were considered, a synergistic interaction was observed (FBC index equal to 0.5) against all tested strains. A synergistic effect was also observed in time-kill assay (a difference of at least 3 log between the combination and the most active agent alone). Scanning electron microscopy (SEM) was used to visualise the changes in the bacterial membrane. The holes in bacterial envelope and leakage of cellular contents were observed in SE micrographs after exposure to the EOs–LNCs and the doxycycline combination.
Keywords: Doxycycline; Synergy; Lipid nanocapsules; Essential oils; Resistant bacteria;

Mutual interaction between guest drug molecules and host nanoporous silica xerogel studied using central composite design by Jing Li; Hongyu Wang; Heran Li; Lu Xu; Yingyu Guo; Fangzheng Lu; Weisan Pan; Sanming Li (32-39).
Display OmittedIn the present study, three water-soluble drugs (propranolol hydrochloride, PNH; diltiazem hydrochloride, DZH; levofloxacin hydrochloride, LFH) with different number of hydrogen bonding acceptors were used as guest drug molecules, and three kinds of biomimetic synthesized nanoporous silica@poly(ethyleneimine)s xerogel (NS@P xerogel, 25%NS@P xerogel and 75%NS@P xerogel) were taken as host drug carriers. Mutural interaction formed between guest drug molecules and host drug carriers were investigated using a two-level three-factorial central composite design. The results confirmed that water-soluble drug loaded three nanoporous silica carriers presented the same regular controlled release effect, which was 75%NS@P xerogel > 25%NS@P xerogel > NS@P xerogel. The main contribution to burst release was the pore diameter of host carrier. Accomplishment of cumulative release in 24 h can be obtained when loading guest drug molecules with small number of hydrogen bonding acceptors to host carriers with either quite small or large pore diameter. The present work can favor to explore the mutural interaction between host carrier and guest drug molecules and thus promoted the development of nanoporous silica in pharmaceutical application.
Keywords: Nanoporous silica xerogel; Controlled release; Central composite design; Water-soluble drugs;

TKD peptide as a ligand targeting drug delivery systems to memHsp70-positive breast cancer by Ying Meng; Shanshan Wang; Chengyi Li; Min Qian; Yufan Zheng; Xueying Yan; Rongqin Huang (40-48).
Display OmittedBreast cancer has been considered as a serious threat to females’ life. Active targeting drug delivery is a potential strategy in cancer therapy, which however is hindered by the targeting efficiency. Herein, a 14-mer peptide (TKD) derived from the oligomerization domain of membrane heat-shock protein 70 (memHsp70), for the first time, was exploited as a tumor-targeting ligand to modify polymeric micelles. NMR results demonstrated the successful synthesis of TKD-PEG-PLGA polymer. No difference was observed in the drug release between TKD-modified doxorubicin (DOX)-loaded micelles (TKD-D-M) and unmodified counterparts. The modification of TKD mediated apparently higher cellular uptake within memHsp70-positive MCF-7 cells, compared to normal MCF-10A cells. Excessive TKD pretreatment significantly inhibited the cellular uptake of TKD-D-M, indicating the receptor-mediated mechanism. Enhanced accumulation of TKD-D-M within the tumor of MCF-7 bearing mice further demonstrated the targeting ability of TKD in vivo. CCK-8 assay showed that the modification of TKD significantly increase the anti-proliferation effect against MCF-7 cells. The findings demonstrated that TKD peptide is a potential ligand which can target drug delivery systems to memHsp70-positive breast cancer.
Keywords: TKD peptide; memHsp70; Active targeting; Micelles; Breast cancer;

Evaluation of the versatile character of a nanoemulsion formulation by E. Gué; M. Since; S. Ropars; R. Herbinet; L. Le Pluart; A. Malzert-Fréon (49-65).
Display OmittedThe formulate-ability of six model active pharmaceutical ingredients (API), with different physico-chemical profiles, in a nanoemulsion designed to be intraveinously administrable was explored. Nanoemulsions were spontaneously generated at room temperature by pouring a phosphate buffer in an anhydrous mixture containing pharmaceutically acceptable triglycerides and non-ionic surfactants. After determination of the apparent solubility of each API in excipients and characterization of mixtures by DSC, API-loaded nanoemulsions were formulated and characterized in terms of granulometric properties, surface potential, drug recovery efficiency, pH, osmolarity, in vitro drug release, and stability.Except ciprofloxacin, a BCS class IV drug, all studied APIs were soluble in at least one excipient used, i.e. Labrasol®. At 2 wt% API, all drug-loaded nanoemulsions present properties compatible with i.v. administration. The formulation should permit to increase apparent solubility of poorly water-soluble APIs, and also to prolong delivery of hydrophobic as well of more hydrophilic compounds. Herein, the relative affinity of the API for nanodroplets and the release medium would directly influence drug release profiles. Nanoemulsions were stable for 7 days. They could also been extemporaneously reconstituted before use. Such a versatile nanoemulsion would provide a valuable option as formulation strategy for improvement of drug properties.
Keywords: Nanoemulsion; Self-emulsification; Labrasol®; Apparent solubility; Parenteral administration;

Tween 20 increases intestinal transport of doxorubicin in vitro but not in vivo by Amal Al-Saraf; René Holm; Carsten Uhd Nielsen (66-69).
Display OmittedThe chemotherapeutic drug substance doxorubicin has been reported to be a substrate of P-gp, which induces a barrier for oral administration and leads to a bioavailability of 3% in male Sprague Dawley rats. Literature studies have reported increased transport of P-pg substrates, like digoxin, when co-administered with P-gp inhibitors (non-ionic surfactants) in vitro and in vivo . The aim of the present study was thus to investigate if different non-ionic surfactants would have a similar effect on the in vitro and in vivo absorption of doxorubicin. This was investigated in vitro in Caco-2 cells and by oral co-administration of doxorubicin together with tween 20 to male Sprague Dawley rats. 200 μM (0.025%) tween 20 increased the intestinal absorptive permeability of doxorubicin in vitro by 48 ± 4% from 8.8 × 10−6  cm/s to 13.0 × 10−6  cm/s. Further, the efflux ratio was reduced from 2.2 ± 0.06 to 1.2 ± 0.03 (n  = 3–7). In vivo, co-administration of doxorubicin and 0–25% tween 20 did not yield detectable doxorubicin plasma concentrations, probably due to extensive intestinal metabolism. In conclusion, the present study demonstrated that non-ionic surfactants increased the transport of doxorubicin in vitro, most likely by inhibition of the efflux activity. However, this effect was not transferable to the in vivo situation.
Keywords: Caco-2 cells; Doxorubicin; Surfactants; In vivo; Rats; P-gp; Inhibitor;

Display OmittedThe conventional chemotherapeutic agent doxorubicin hydrochloride (DOX·HCl) is often accompanied by drug resistance which has severely hindered its clinical application. By taking advantage of the self-assembled behavior of amphiphilic polyphosphazenes, we constructed novel polymersomes loading DOX·HCl or desalted DOX with chloroquine phosphate (CQ) as a drug resistance-reversal agent at 1:1 or 2:1 weight ratios via a one-step common dialysis method. The cytotoxicity evaluation of this dual drug-loaded polymersome was performed on DOX-resistant MCF-7/Adr breast cancer and HL60/Adr leukemia cells. Simultaneously, to simulate in vivo cancerous tissue, 3D tumor spheroid was constructed for tissue penetration and anti-cancer effect evaluation. As a result, PEP-DHC-1 containing DOX·HCl and CQ at 1:1 weight ratio exhibited the strongest toxicity. Furthermore, the in vivo tumor inhibition study carried out on a zebrafish xenograft model also validated that PEP-DHC-1 made the outstanding contribution to improve the sensitivity of MCF-7/Adr breast cancer to chemotherapeutics. These findings suggest that this DOX·HCl and CQ co-delivery system based on PEP polymersomes might be promising for drug resistance reversal of cancer therapy and consequently enhanced anti-cancer efficacy.
Keywords: Polyphosphazene; Polymersomes; Doxorubicin; Chloroquine; Drug resistance; Combination cancer therapy;

Display OmittedCurrently, most of the approved protein and peptide-based medicines are delivered via conventional parenteral injection (intramuscular, subcutaneous or intravenous). A frequent dosing regimen is often necessary because of their short plasma half-lives, causing poor patient compliance (e.g. pain, abscess, etc.), side effects owing to typical peak-valley plasma concentration time profiles, and increased costs. Among many sustained-release formulations poly lactic-co-glycolic acid (PLGA)-based depot microparticle systems may represent one of the most promising approaches to provide protein and peptide drugs with a steady pharmacokinetic/pharmacodynamic profile maintained for a long period. However, the development of PLGA-based microparticle systems is still impeded by lack of easy, fast, effective manufacturing technologies. The aim of this paper is to review recent advances in spray drying, a one-step, continuous microencapsulation process, for manufacturing of PLGA-based depot microparticle systems with a focus on the recent efforts on understanding of the role of nozzle design in the microencapsulation of proteins/peptides, and the effect of critical solvent properties and process parameters on the critical quality attributes of the spray-dried microparticles.
Keywords: Spray drying; Microencapsulation; Poly lactic-glycolic acid (PLGA); Sustained release; Proteins and peptides;

Development of prilling process for biodegradable microspheres through experimental designs by Violet Fabien; Le Minh-Quan; Sergent Michelle; Bastiat Guillaume; Tran Van-Thanh; Venier-Julienne Marie-Claire (96-109).
Display OmittedThe prilling process proposes a microparticle formulation easily transferable to the pharmaceutical production, leading to monodispersed and highly controllable microspheres. PLGA microspheres were used for carrying an encapsulated protein and adhered stem cells on its surface, proposing a tool for regeneration therapy against injured tissue. This work focused on the development of the production of PLGA microspheres by the prilling process without toxic solvent. The required production quality needed a complete optimization of the process. Seventeen parameters were studied through experimental designs and led to an acceptable production. The key parameters and mechanisms of formation were highlighted.
Keywords: Prilling; PLGA; Microsphere; Experimental design; Glycofurol;

Chitosan encapsulated multifunctional magneto-fluorescent nanocomposites were synthesized and characterized using different spectroscopy and microscopy techniques. The in vitro imaging and staining studies suggested presence of both fluorescent as well as magnetically active materials inside cellular environment. The in vivo biodistribution and toxicity studies revealed that these nanocomposites might find their application as efficient bimodal imaging probe for biological systems.Display OmittedMultifunctional hybrid nanocomposite material, consists of chitosan encapsulated iron oxide (as MRI contrasting agent), CdS (as fluorescent probe) nanoparticles and podophyllotoxin (as anticancer drug) was synthesized and characterized. The TEM studies suggested the size of the NPs to be in the range of 80–100 nm. These nanocomposites were treated with different cancer cell lines viz., KB, C6 and A549 cells. Fluorescence imaging and Perl’s Prussian blue staining confirmed the presence of these nanocomposites inside both KB and C6 cells but not in A549 cells. Cytotoxicity experiments revealed that these biopolymer coated nanocomposites showed minimal toxicity towards cancerous cells. Further the intraperitoneal administration of one of the nanoformulations to Wistar rats suggested deposition of these nanocomposites in the lungs. The hematological, biochemical and histopathological analysis confirmed that these nanocomposites are safe to use as a novel dual mode imaging material.
Keywords: Chitosan nanoparticles; Fluorescence imaging; Perl’s Prussian blue staining; Histopathology; Hematology;

Effect of particle size on the biodistribution of nano- and microparticles following intra-articular injection in mice by Julie Pradal; Pierre Maudens; Cem Gabay; Christian Alexander Seemayer; Olivier Jordan; Eric Allémann (119-129).
Intra-articular injection of drug delivery systems: retention in the joint cavity or elimination through blood and lymphatic pathways depending on the size of the particles and the inflammatory status of the joint.Display OmittedIntra-articular (IA) injection of extended drug release forms based on biodegradable microparticles holds promise for the treatment of joint diseases. However, the fate of microparticles following intra-articular injection is controversial and has not been thoroughly investigated. The aim of this work was therefore to evaluate the biodistribution of fluorescent poly(lactic acid) particles of different sizes after IA injection in arthritic or healthy mice.Regardless of the inflammatory status of the joint, 300 nm-nanoparticles leaked from the joint. Due to inflammation and related increase of vascular permeability, 3 μm-microparticles that were retained in the non-inflamed synovial membrane leaked from the inflamed joint. Complete retention of 10 μm-microparticles was observed independently of the joint inflammatory status. Embedding particles in a hyaluronic acid gel prolonged the retention of the formulations only in inflamed joints. Depending on particle’s size, formulations were preferentially eliminated by blood vessels or lymphatic pathways. Poly(lactic acid) particles of 3 μm were biocompatible and retained in knee joints at least for 6 weeks.This work highlights the need to deliver hyaluronic acid-embedded particles of at least 3 μm to guarantee their retention in inflamed joints. These results will contribute to the rational design of long-lasting formulations to treat acute and chronic joint diseases.
Keywords: Microparticles; Arthritic diseases; Hyaluronic acid; Synovial membrane; In vivo biodistribution; Intra-articular administration;

Double emulsions based on silicone-fluorocarbon-water and their skin penetration by Denise-Silvia Mahrhauser; Claudia Fischer; Claudia Valenta (130-133).
Display OmittedDouble emulsions have significant potential in pharmacy and cosmetics due to the feasibility of combining incompatible substances in one product and the protection of sensitive compounds by incorporating them into their innermost phase. However, a major drawback of double emulsions is their thermodynamic instability and their strong tendency to coalesce. In the present study, the physicochemical stability, the skin permeation and the skin penetration potential of modified semi-solid double emulsions was investigated. The double emulsions were prepared of the cosmetically applied perfluoropolyethers Fomblin® HC/04 or Fomblin® HC-OH, silicone, carbomer and water. Measurement of the droplet size and examination of the microscopic images confirmed their physicochemical stability over the observation period of eight weeks. Franz-type diffusion cell experiments revealed no increase in curcumin permeation due to the employed perfluoropolyethers compared to the respective control formulations. The formulations used as control were O/W macroemulsions with or without a Polysorbate 80/Sorbitane monooleate 80 surfactant combination. Likewise, tape stripping studies showed no penetration enhancing effect of the employed perfluoropolyethers which is desirable as both perfluoropolyethers are commonly applied components in human personal-care products.
Keywords: Perfluoropolyethers; Double emulsion; Skin permeation; Skin penetration; Stability;

Synergistic effect of PEGylated resveratrol on delivery of anticancer drugs by Wenlong Wang; Liang Zhang; Yuan Le; Jian-Feng Chen; Jiexin Wang; Jimmy Yun (134-141).
Display OmittedResveratrol (RES) is a natural polyphenol which can be considered as a nutraceutical because of its benefits such as anticancer and antioxidant activity. In this paper, we designed polymer-RES conjugates as anticancer drug carrier for synergistic therapeutic effect in cancer treatment. Bicalutamide (BIC) was used as a model drug to investigate the drug release behaviors and in vitro anticancer performance. PEG-RES and PEG-Glycine-RES nanoparticles were prepared and characterized. The size of the prepared particles was around 50 nm with RES content of 17.2 and 16.3 wt% for PEG-RES and PEG-Glycine-RES, respectively, and BIC loading efficiency were of 81.6% and 84.5%, separately. Release rate of RES from conjugates depended on the stability of ester group against hydrolysis. BIC release was much faster than RES release. The anticancer activity of BIC loaded PEGylated RES nanoparticles was much better than that of free BIC, indicating the conjugates provided a synergetic cytotoxicity to cancer cells. Confocal laser scanning microscopy observation and flow cytometry analyses indicated that PEGylated RES conjugates were more efficiently internalized into cells, released drug into cytoplasm. These results suggest that PEGylated RES conjugates show great potential for cancer therapy.
Keywords: PEGylated RES; Conjugates; Anticancer; Synergistic effect;

Preformulation and characterization of a lidocaine hydrochloride and dexamethasone sodium phosphate thermo-reversible and bioadhesive long-acting gel for intraperitoneal administration by Diana Arbelaez-Camargo; Josep Maria Suñé-Negre; Manel Roig-Carreras; Encarna García-Montoya; Pilar Pérez-Lozano; Montserrat Miñarro-Carmona; Josep Ramon Ticó-Grau (142-152).
Display OmittedThe search for new formulations of anaesthetic agents that allow a localized administration and provide a prolonged effect is of great interest in the multimodal management of postoperative pain. The pre-formulation and characterization of a lidocaine and dexamethasone thermosensitive and bioadhesive long-acting gel for intraperitoneal administration was done as a tool in the management of pain in abdominal surgeries. The pre-formulation process was conducted by a systematic variation of the concentration of the different polymers, until setting it, in a suitable concentration that allowed an adequate gelation temperature. The poloxamer 407 (P407) was used as the main polymer; hydroxypropyl methylcellulose (HPMC) as the bioadhesive agent and polyvinyl pyrrolidone (PVP) to adjust the gelation temperature and physicochemical properties. The formulations were characterized by gelation temperature, pH, viscosity at 25 °C and 37 °C, gelation time, density and osmolality. Gelation temperature was decreased when increasing the concentration of hydroxypropyl methylcellulose and poloxamer 407, this effect was also observed when adding lidocaine hydrochloride and dexamethasone sodium phosphate to the formulations. The gelation temperature did not have statistically significant relation with the PVP concentration (P-value of 0.6797), even though, there is a tendency in the gelation temperature by varying it. Between the developed formulations, the 12.5/3.3/0.4% (P407/HPMC/PVP) formulation presents an appropriate gelation temperature, a suitable viscosity for administration by syringe, an adequate and stable pH and osmolality to prevent tissue damage and a correct gelation time that allowed the formation of a prolonged release implant.
Keywords: Thermoreversible gel; Controlled release; Bioadhesive; Poloxamer 407; Intraperitoneal administration; Lidocaine; Dexamethasone;

Formulation design and evaluation of amorphous ABT-102 nanoparticles by Rajan Jog; Sumit Kumar; Jie Shen; Nital Jugade; David Cheng Thiam Tan; Rajeev Gokhale; Diane J. Burgess (153-169).
Display OmittedAmorphous nanoparticles are able to enhance the kinetic solubility and concomitant dissolution rates of BCS class II and BCS class II/IV molecules due to their characteristic increased supersaturation levels, smaller particle size and greater surface area. A DoE approach was applied to investigate formulation and spray drying process parameters for the preparation of spray dried amorphous ABT-102 nanoparticles. Stability studies were performed on the optimized formulations to monitor physical and chemical changes under different temperature and humidity conditions. SLS/soluplus® and SLS/PVP K25 were the best stabilizer combinations. Trehalose was used to prevent nanoparticle aggregation during spray drying. Particle size distribution, moisture content, PXRD, PLM, FTIR and in vitro dissolution were utilized to characterize the spray dried nanoparticle formulations. The formulations prepared using soluplus® showed enhanced dissolution rate compared to those prepared using PVP K25. Following three months storage, it was observed that the formulations stored at 4 °C were stable in terms of particle size distribution, moisture content, and crystallinity, whereas those stored at 25 °C/60%RH and 40 °C/75%RH were unstable. A predictive model to prepare stable solid spray dried amorphous ABT-102 nanoparticles, incorporating both formulation and process parameters, was successfully developed using multiple linear regression analysis.
Keywords: Amorphous nanoparticles; DoE; In vitro dissolution testing; Spray drying;

Ex-Vivo percutaneous absorption of enrofloxacin: Comparison of LMOG organogel vs. pentravan cream by Plamen Kirilov; Van Hung Tran; Alban Ducrotté-Tassel; Jean-Paul Salvi; Sébastien Perrot; Marek Haftek; Roselyne Boulieu; Fabrice Pirot (170-177).
The percutaneous permeation through pig skin of two formulations containing 5 wt% of enrofloxacin was measured and compared using Franz diffusion cells. Enrofloxacin immobilized in a LMOG organogel could be absorbed through pig ear skin 3.7 times greater than that in Pentravan® (commercial formulation). This study demonstrates the perspective of organogel formulations as potential drug delivery systems.Display OmittedThe objective of this study was to investigate the percutaneous absorption of enrofloxacin from two base formulations, Pentravan® cream and LMOG organogel. Ex-vivo experiments were carried out on pig ear skin. The percutaneous permeation through pig skin of two formulations containing 5 wt% of enrofloxacin was measured and compared using Franz diffusion cells. At appropriate intervals up to 120 h, diffusion samples were taken and analyzed using HPLC assays. Permeation profiles were established and the parameters T lag and flux values were calculated. In this ex-vivo study, the flux values were 0.35 μg cm−2  h−1 for Pentravan® and 1.22 μg cm−2  h−1 for LMOG organogel, corresponding respectively to 7.9 % and 29.3 % of enrofloxacin absorbed after 120 h by these formulations. The lag time (T lag) of Pentravan® and organogel were 6.32 and 0.015 h respectively. The absorption time to reach the antibiotic concentration of enrofloxacin (2 μg mL−1) in the receptor was 60 h with Pentravan® and 30 h with the organogel, suggesting more effective treatment by the latter. Enrofloxacin contained in organogel could be absorbed through pig ear skin 3.7 times greater than that in Pentravan® (commercial formulation). This study demonstrates the perspective of organogel formulations as potential drug delivery systems.
Keywords: Enrofloxacin; In-vitro percutaneous absorption; LMOG organogel; Pentravan®; HPLC quantification;

Display OmittedPharmaceutical research needs predictive in vitro tools for API bioavailability in humans. We evaluated two dynamic in vitro gastrointestinal models: TIM-1 and tiny-TIM. Four low-soluble APIs in various formulations were investigated in the TIM systems under fasted and fed conditions. API small-intestinal bioaccessibility profiles were evaluated between the two systems and in comparison with human data. Both TIM systems showed a higher bioaccessibility of ciprofloxacin and nifedipine during 3–4 h after dosing immediate release (IR) compared to modified release (MR) formulations. Higher bioaccessibility levels from IR formulations were observed under fasted state in the first 30–90 min in tiny-TIM as compared to TIM-1, resulting in a t max similar to clinical data. Absence (ciprofloxacin) or presence (posaconazole) of a food effect on bioaccessibility was observed in both TIM systems in line with human data. A higher bioaccessibility of fenofibrate from nano- vs micro-particle formulation was found in both TIM systems. This dataset shows the predictive quality of the TIM systems for clinical data on API small-intestinal bioaccessibility from IR and MR formulations and food effects. Tiny-TIM provides higher throughput and better prediction for IR formulations. TIM-1 provides detailed information on site-specific release of APIs, relevant for MR formulations and food effects.
Keywords: In vitro gastrointestinal model; Oral dosage form; Pharmaceutical bioaccessibility; TIM system; Food effect;

Live RB51 vaccine lyophilized hydrogel formulations with increased shelf life for practical ballistic delivery by Jonathan L. Falconer; R. James Christie; Emily J. Pollard; Steven C. Olsen; David W. Grainger (187-194).
Display OmittedBallistic delivery capability is essential to delivering vaccines and other therapeutics effectively to both livestock and wildlife in many global scenarios. Here, lyophilized poly(ethylene glycol) (PEG)-glycolide dimethacrylate crosslinked but degradable hydrogels were assessed as payload vehicles to protect and deliver a viable bacterial vaccine, Brucella abortus strain RB51 (RB51), ballistically using commercial thermoplastic cellulosic degradable biobullets. Degradable PEG hydrogel rods loaded with ∼1010 live RB51 bacteria (CFUs) were fabricated using three different polymerization methods, cut into fixed-sized payload segments, and lyophilized. Resulting dense, glassy RB51 vaccine-loaded monoliths were inserted into thermoplastic biobullet 100-μL payload chambers. Viability studies of lyophilized formulations assessed as a function of time and storage temperature supported the abilities of several conditions to produce acceptable vaccine shelf-lives. Fired from specifically designed air rifles, gel-loaded biobullets exhibit down-range ballistic properties (i.e., kinetic energy, trajectory, accuracy) similar to unloaded biobullets. Delivered to bovine tissue, these hydrogels rehydrate rapidly by swelling in tissue fluids, with complete hydration observed after 5 h in serum. Live RB51 vaccine exhibited excellent viability following carrier polymerization, lyophilization, and storage, at levels sufficient for vaccine dosing to wild range bison, the intended target. These data validate lyophilized degradable PEG hydrogel rods as useful drug carriers for remote delivery of both live vaccines and other therapeutics to livestock, wildlife, or other free-range targets using ballistic technologies.
Keywords: Wildlife; Animal health; Brucellosis; Remote delivery; Bison; Polymerization; Bio-bullet; Polyethylene glycol;

Intracellular Doxorubicin Delivery of a Core Cross-linked, Redox-responsive Polymeric Micelles by Yu. Lili; Mu. Ruihua; Li. Li; Liang. Fei; Yao. Lin; Su. Li (195-204).
Display OmittedRedox-responsive micelles based on amphiphilic polyethylene glycol-polymethyl methacrylate with the introduction of disulfide containing cross-linked agent (mPEG-PMMA-SS) were developed for intracellular drug release. Benefiting from the amphiphilicity, mPEG-PMMA-SS could self-assembled into core cross-linked micelles in aqueous medium with tunable sizes (85–151 nm), appropriate zeta potential (−24.8 mV), and desirable critical micelle concentration (CMC) (0.18 mg/mL). Doxorubicin (DOX) could efficiently load into the micelles with satisfactory entrapment efficiency. As expected, the in vitro release studies displayed that DOX release from mPEG-PMMA-SS micelles was about 75% within 10 h under tumor-relevant reductive condition, whereas only about 25% DOX was released in non-reductive medium. SRB assays indicated that these mPEG-PMMA-SS micelles were biocompatible and nontoxic up to a concentration of 50 μg/mL. The cytotoxicity studies and the intracellular drug delivery demonstrated that the drug release behavior in cells was related to the concentration of GSH in cytoplasm. Furthermore, the cell experiments using fluorescence microscopy showed clearly that DOX was delivered by micelles to the cytoplasm, released in cytoplasm under reductive environment, and then accumulated in cell nucleus. These results suggest that such redox-responsive micelles may develop into an efficient cytoplasmic delivery for hydrophobic anticancer drugs.
Keywords: Micelles; Redox-responsive; Disulfide bonds; Intracellular drug delivery; Core cross-linked;

l-Type amino acid transporter 1 (lat1)-mediated targeted delivery of perforin inhibitors by Kristiina M. Huttunen; Johanna Huttunen; Imke Aufderhaar; Mikko Gynther; William A. Denny; Julie A. Spicer (205-216).
Display OmittedPerforin is a cytolytic pore-forming glycoprotein secreted by cytotoxic effector cells. It is a key component of the immune response against virus-infected and transformed cells and has been implicated in a number of human diseases. Perforin activity can be inhibited by small-molecular-weight compounds, although less is known about their delivery to the site of action. Therefore, in the present study, it was explored if perforin inhibitors could be efficiently and site-selectively delivered firstly into the cytotoxic effector cells and secondly into lytic granules, in which perforin is stored. This was accomplished by designing and synthesizing four prodrugs of perforin inhibitors that could utilize l-type amino acid transporter (LAT1), since activated immune cells are known to over-express LAT1. The results demonstrate that cellular uptake of perforin inhibitors can be increased by LAT1-utilizing prodrugs (into human breast adenocarcinoma cells (MCF-7)). Furthermore, these prodrugs were also able to deliver perforin inhibitors into the cell organelles having lower pH (rat liver lysosomes). Therefore, by using these prodrugs, intracellular mechanisms of perforin inhibitory activity can be studied more thoroughly in future. Moreover, this prodrug approach can be applied for other drugs that would benefit from targeted delivery into cells expressing LAT1, such as cancer.
Keywords: Prodrug; Perforin inhibitor; l-type amino acid Transporter 1 (LAT1); Targeted drug delivery; Transporter-mediated drug delivery;

Amorphous cyclosporin A nanoparticles for enhanced dermal bioavailability by Gregori B. Romero; Anja Arntjen; Cornelia M. Keck; Rainer H. Müller (217-224).
Display OmittedCylosporin A (CyA) was formulated as amorphous nanoparticle suspension to increase dermal penetration, e.g. applicable in psoriasis. The suspension consisted of 5% CyA in water, stabilized with vitamin E polyethylene glycol succinate (TPGS, Kolliphor® TPGS) and was produced by bead milling. The diameter of the bulk population was about 350 nm, laser diffraction diameter 99% was 690 nm. The suspension was physically stable over one year of storage at room temperature, and most important the amorphous state also remained stable. Despite the high dispersitivity and related large surface area in contact with water, the drug content reduced only by 5% over 1 year of storage. i.e. the formulation is feasible as commercial product with expiry date. The CyA nanoparticles and μm-sized CyA particles were incorporated into hydroxypropylcellulose (HPC) gels and the penetration studied into fresh pig ear skin applying the tape stripping method. At tape number 30, the penetrated cumulative amount of CyA from nanoparticles was 6.3 fold higher compared to the μm-sized raw drug powder (450.1 μg/cm2 vs. 71.3 μg/cm2). A theoretical mechanism is presented to explain the observed superiority in penetration. Based on amorphous CyA nanoparticles, dermal formulations for improved dermal CyA delivery seem to be feasible.
Keywords: Nanoparticles; Nanocrystals; Nanosuspension; Dermal; Cyclosporin A; Amorphous;

An in vitro study of mucoadhesion and biocompatibility of polymer coated liposomes on HT29-MTX mucus-producing cells by Małgorzata I. Adamczak; Ellen Hagesaether; Gro Smistad; Marianne Hiorth (225-233).
Display OmittedDrug delivery to the oral cavity poses a significant challenge due to the short residence time of the formulations at the site of action. From this point of view, nanoparticulate drug delivery systems with ability to adhere to the oral mucosa are advantageous as they could increase the effectiveness of the therapy. Positively, negatively and neutrally charged liposomes were coated with four different types of polymers: alginate, low-ester pectin, chitosan and hydrophobically modified ethyl hydroxyethyl cellulose. The mucoadhesion was studied using a novel in vitro method allowing the liposomes to interact with a mucus-producing confluent HT29-MTX cell-line without applying any external force. MTT viability and paracellular permeability tests were conducted on the same cell-line. The alginate-coated liposomes achieved a high specific (genuine) mucin interaction, with a low potential of cell-irritation. The positively charged uncoated liposomes achieved the highest initial mucoadhesion, but also displayed a higher probability of cell-irritation. The chitosan-coated liposomes displayed the highest potential for long lasting mucoadhesion, but with the drawback of a higher general adhesion (tack) and a higher potential for irritating the cells.
Keywords: Liposomes; Polymers; Mucoadhesion; MTT viability test; Paracellular permeation; HT29-MTX cells;

Detailed stability investigation of amorphous solid dispersions prepared by single-needle and high speed electrospinning by B. Démuth; A. Farkas; H. Pataki; A. Balogh; B. Szabó; E. Borbás; P.L. Sóti; T. Vigh; É. Kiserdei; B. Farkas; J. Mensch; G. Verreck; I. Van Assche; G. Marosi; Z.K. Nagy (234-244).
Display OmittedIn this research the long-term stability (one year) of amorphous solid dispersions (ASDs) prepared by high speed electrospinning was investigated at 25 °C/60% relative humidity (RH) (closed conditions) and 40 °C/75% RH (open conditions). Single needle electrospinning and film casting were applied as reference technologies. Itraconazole (ITR) was used as the model API in 40% concentration and the ASDs consisted of either one of the following polymers as a comparison: polyvinylpyrrolidone-vinyl acetate 6:4 copolymer (no hydrogen bonds between API and polymer) and hydroxypropyl methylcellulose (possible hydrogen bonds between oxo or tertiary nitrogen function of API and hydroxyl moiety of polymer). DSC, XRPD and dissolution characteristics of samples at 0, 3 and 12 months were investigated. In addition, Raman maps of certain electrospun ASDs were assessed to investigate crystallinity. A new chemometric method, based on Multivariate Curve Resolution-Alternating Least Squares algorithm, was developed to calculate the spectrum of amorphous ITR in the matrices and to determine the crystalline/amorphous ratio of aged samples. As it was expected ITR in single needle electrospun SDs was totally amorphous at the beginning, in addition hydroxypropyl methylcellulose could keep ITR in this form at 40 °C/75% RH up to one year due to the hydrogen bonds and high glass transition temperature of the SD. In polyvinylpyrrolidone-vinyl acetate matrix ITR remained amorphous at 25 °C/60% RH throughout one year. Materials prepared by scaled-up, high throughput version of electrospinning, which is compatible with pharmaceutical industry, also gained the same quality. Therefore these ASDs are industrially applicable and with an appropriate downstream process it would be possible to bring them to the market.
Keywords: High speed electrospinning; Amorphous solid dispersion; Long-term stability; Raman mapping; Oral drug delivery;

Comparison of the mucoadhesive properties of thiolated polyacrylic acid to thiolated polyallylamine by Sarah Duggan; Orla O’Donovan; Eleanor Owens; Elaine Duggan; Helen Hughes; Wayne Cummins (245-253).
Display OmittedSynthetic polymers, polyacrylic acid (PAA) and polyallylamine (PAAm), were thiolated using different methods of thiolation. Both polymers resulted in comparable thiol contents, thus allowing for the direct comparison of mucoadhesive and cohesive properties between the well-established thiolated PAA and the more novel thiolated PAAm. Thiolation of both polymers improved the swelling ability and the cohesive and mucoadhesive properties in comparison to unmodified control samples. In this study, it was shown that the swelling abilities of the thiolated PAAm sample were far greater than that of the thiolated PAA sample which, in turn, affected the drug release profile of the thiolated PAAm sample. Importantly, however, the mucoadhesive properties of thiolated PAAm were equivalent to that of the thiolated PAA sample as demonstrated by both the adhesion times on porcine intestinal tissue as measured by the rotating cylinder method and by rheological studies with a mucin solution. This study demonstrates the potential thiolated polyallylamine has as a mucoadhesive drug delivery device.
Keywords: Mucoadhesion; Polyacrylic acid; Polyallylamine; Thiolation; Traut’s reagent;

The impact of hot-melt extrusion on the tableting behaviour of polyvinyl alcohol by W. Grymonpré; W. De Jaeghere; E. Peeters; P. Adriaensens; J.P. Remon; C. Vervaet (254-262).
Display OmittedThere is evidence that processing techniques like hot-melt extrusion (HME) could alter the mechanical properties of pharmaceuticals, which may impede further processability (e.g. tableting). The purpose of this study was to evaluate if HME has an impact on the tableting behaviour of polyvinyl alcohol (PVA)-formulations. Mixtures of partially hydrolysed PVA grades (with a hydroxylation degree of 75 and 88%) and sorbitol (0, 10 and 40%) were extruded, (cryo-) milled and compressed into compacts of 350 ± 10 mg. Before compression all intermediate products were characterized for their solid-state (T g, T m, crystallinity) and material properties (particle size, moisture content, moisture sorption). Because both PVA-grades required higher extrusion temperatures (i.e. 180 °C), sorbitol was added to PVA as plasticizing agent to allow extrusion at 140 °C. Compaction experiments were performed on both physical mixtures and cryo-milled extrudates of PVA-sorbitol. By measuring tablet tensile strength and porosity in function of compaction pressure, tableting behaviour was compared before and after HME by means of the CTC-profiles (compressibility, tabletability, compactibility). A higher amorphous content in the formulation (as a result of HME) negatively influenced the tableting behaviour (i.e. lower tablet tensile strength). HME altered the mechanical properties towards more elastically deforming materials, thereby increasing tablet elastic recovery during decompression. The lower tensile strengths resulted from a combined effect of less interparticulate bonding areas (because of higher elastic recovery) and weaker bonding strengths per unit bonding area (between glassy particles).
Keywords: Hot-melt extrusion; Tableting; Elastic recovery; Polyvinyl alcohol; Oral drug delivery; Immediate release;

Pulmonary delivery of tobramycin-loaded nanostructured lipid carriers for Pseudomonas aeruginosa infections associated with cystic fibrosis by María Moreno-Sastre; Marta Pastor; Amaia Esquisabel; Eulàlia Sans; Miguel Viñas; Aarne Fleischer; Esther Palomino; Daniel Bachiller; José Luis Pedraz (263-273).
Display OmittedAmong the pathogens that affect cystic fibrosis (CF) patients, Pseudomonas aeruginosa is the most prevalent. As a way to fight against this infection, nanotechnology has emerged over the last decades as a promising alternative to overcome resistance to antibiotics in infectious diseases. The goal of this work was to elaborate and characterize lipid nanoparticles for pulmonary delivery of tobramycin.Tobramycin-loaded nanostructured lipid carriers (Tb-NLCs) were prepared by hot melt homogenization technique. In addition, nanoparticles labeled with infrared dye (IR-NLCs) were used to investigate their in vivo performance after pulmonary administration.Tb-NLCs displayed a mean diameter size around 250 nm, high drug encapsulation (93%) and sustained release profile. Tb-NLCs showed to be active against clinically isolated P. aeruginosa. Moreover, Tb-NLCs did not decrease cell viability and were able to overcome an artificial mucus barrier in the presence of mucolytics agents. During the in vivo assay, IR-NLCs were administered to several mice by the intratracheal route using a Penn Century® device. Next, the biodistribution of the nanoparticles was analyzed at different time points showing a wide nanosystem distribution in the lungs.Altogether, tobramycin-loaded NLCs seem to us an encouraging alternative to the currently available CF therapies.
Keywords: Tobramycin; Lipid nanoparticles; Nanocarriers; Cystic fibrosis; Pulmonary administration; Pseudomonas aeruginosa;

A reproducible accelerated in vitro release testing method for PLGA microspheres by Jie Shen; Kyulim Lee; Stephanie Choi; Wen Qu; Yan Wang; Diane J. Burgess (274-282).
Display OmittedThe objective of the present study was to develop a discriminatory and reproducible accelerated in vitro release method for long-acting PLGA microspheres with inner structure/porosity differences. Risperidone was chosen as a model drug. Qualitatively and quantitatively equivalent PLGA microspheres with different inner structure/porosity were obtained using different manufacturing processes. Physicochemical properties as well as degradation profiles of the prepared microspheres were investigated. Furthermore, in vitro release testing of the prepared risperidone microspheres was performed using the most common in vitro release methods (i.e., sample-and-separate and flow through) for this type of product. The obtained compositionally equivalent risperidone microspheres had similar drug loading but different inner structure/porosity. When microsphere particle size appeared similar, porous risperidone microspheres showed faster microsphere degradation and drug release compared with less porous microspheres. Both in vitro release methods investigated were able to differentiate risperidone microsphere formulations with differences in porosity under real-time (37 °C) and accelerated (45 °C) testing conditions. Notably, only the accelerated USP apparatus 4 method showed good reproducibility for highly porous risperidone microspheres. These results indicated that the accelerated USP apparatus 4 method is an appropriate fast quality control tool for long-acting PLGA microspheres (even with porous structures).
Keywords: PLGA microspheres; Porous; Compositionally equivalent; Accelerated in vitro release; Risperidone; USP apparatus 4;

In vitro wound healing and cytotoxic effects of sinigrin–phytosome complex by Anisha Mazumder; Anupma Dwivedi; Jan L. du Preez; Jeanetta du Plessis (283-293).
Display OmittedSinigrin is a class of glucosinolates found naturally in plants of the Brassicaceae family. Lately, studies have shown that sinigrin possesses anticancer, antibacterial and anti-inflammatory activities. Since its efficacy has not been explored on wound healing, we examined the effect of sinigrin on HaCaT cells. We also aimed at formulating sinigrin into phytosome to form a sinigrin–phytosome complex and study the wound healing and cytotoxic activities on A-375 and HaCaT cells. Sinigrin was efficiently formulated into the phytosome with an average particle size of 153 ± 39 nm, zeta potential of 10.09 ± 0.98 mV and complex efficiency of 69.5 ± 5%. The formation of the sinigrin–phytosome complex was confirmed by DSC and FTIR analysis. The sinigrin–phytosome complex significantly exhibited wound healing effects when compared to sinigrin alone. After 42 h, the phytosome complex completely healed the wound, whereas sinigrin alone showed only 71% wound closure. The sinigrin–phytosome complex displayed minimal toxicity towards HaCaT cells and at higher concentrations, it showed potent activity towards A-375. The results indicated that sinigrin–phytosome complex augmented the therapeutic potential of sinigrin towards the wound healing activity and this approach should be explored further for cancerous wound treatment.
Keywords: Sinigrin; Wound healing; Phytosome; Sinigrin–phytosome complex; Cytotoxic;

Influence of surfactants in self-microemulsifying formulations on enhancing oral bioavailability of oxyresveratrol: Studies in Caco-2 cells and in vivo by Yaowaporn Sangsen; Kamonthip Wiwattanawongsa; Kittisak Likhitwitayawuid; Boonchoo Sritularak; Potchanapond Graidist; Ruedeekorn Wiwattanapatapee (294-303).
Display OmittedSelf-microemulsifying drug delivery systems (SMEDDS) containing two types (Tween80® and Labrasol®) and two levels (low; 5% and high; 15%) of co-surfactants were formulated to evaluate the impact of surfactant phase on physical properties and oral absorption of oxyresveratrol (OXY). All formulations showed a very rapid release in the simulated gastric fluid (SGF) pH 1.2. After dilution with different media, the microemulsion droplet sizes of the Tween80®-based (∼26 to 36 nm) were smaller than that of the Labrasol®-based systems (∼34 to 45 nm). Both systems with high levels of surfactant increased the Caco-2 cells permeability of OXY compared to those with low levels of surfactant (1.4–1.7 folds) and the unformulated OXY (1.9–2.0 folds). It was of interest, that there was a reduction (4.4–5.3 folds) in the efflux transport of OXY from both systems compared to the unformulated OXY. The results were in good agreement with the in vivo absorption studies of such OXY-formulations in rats. Significantly greater values of C max and AUC0–10h (p  < 0.05) were obtained from the high levels of Tween80®-based (F r,0–10h 786.32%) compared to those from the Labrasol®-based system (F r,0–10h 218.32%). These finding indicate the importance of formulation variables such as type and quantity of surfactant in the SMEDDS to enhance oral drug bioavailability.
Keywords: Self-microemulsifying drug delivery system; SMEDDS; Surfactants; Caco-2 cells; Oral absorption; Oxyresveratrol;

Different amorphous solid-state forms of roxithromycin: A thermodynamic and morphological study by Marnus Milne; Wilna Liebenberg; Marique Elizabeth Aucamp (304-315).
Display OmittedThe striking impact that different preparation methods have on the characteristics of amorphous solid-state forms has attracted considerable attention during the last two decades. The pursuit of more extensive knowledge regarding polyamorphism therefore continues. The aim of this study was firstly, to investigate the influence of different preparation techniques to obtain amorphous solid-state forms for the same active pharmaceutical ingredient, namely roxithromycin. The preparation techniques also report on a method utilizing hot air, which although it is based on a melt intermediary step, is considered a novel preparation method. Secondly, to conduct an in-depth investigation into any physico-chemical differences between the resulting amorphous forms and thirdly, to bring our findings into context with that of previous work done, whilst simultaneously discussing a well-defined interpretation for the term polyamorphism and propose a discernment between true polyamorphism and pseudo-polyamorphism/atypical-polyamorphism. The preparation techniques included melt, solution, and a combination of solution-mechanical disruption as intermediary steps. The resulting amorphous forms were investigated using differential scanning calorimetry, X-ray powder diffraction, hot-stage microscopy, scanning electron microscopy, and vapor sorption. Clear and significant thermodynamic differences were determined between the four amorphous forms. It was also deduced from this study that different preparation techniques have a mentionable impact on the morphological properties of the resulting amorphous roxithromycin powders. Thermodynamic properties as well as the physical characteristics of the amorphous forms greatly governed other physico-chemical properties i.e. solubility and dissolution.
Keywords: Roxithromycin; Amorphous; Preparation method; Polyamorphism; Pseudo-polyamorphism; Atypical polyamorphism;

The enzyme glycerophosphate dehydrogenase (GPDH) behaves differently when dried either as single droplets in an acoustic levitator or spray dried on a bench-top machine. The GPDH in particles dried in the levitator at a drying gas temperature of 60 °C could not be redispersed in water, whereas spray drying at an outlet temperature of 92 °C produced denaturation but the particles were redissolvable. One difference between the two processes is that the larger levitated droplets take longer to dry than the small spray dried droplets. The slow drying process of the levitated droplet/particle apparently causes denaturation that is sufficient to make the particles non-redispersible. This does not happen on spray drying.
Keywords: Protein; Spray dried; Acoustic levitator; Denature; Solubility;

Method development and validation for pharmaceutical tablets analysis using transmission Raman spectroscopy by Yi Li; Benoît Igne; James K. Drennen; Carl A. Anderson (318-325).
A partial least-squares model developed from a 3-by-3 full factorial design was used to predict niacinamide content in three different tablet datasets: a test set, a specificity set and a validation set. Factors varied in the design were: active ingredient content, excipient content, relative humidity, compression force and amount of niacin spiked in different tablet groups.Display OmittedThe objective of the study is to demonstrate the development and validation of a transmission Raman spectroscopic method using the ICH-Q2 Guidance as a template. Specifically, Raman spectroscopy was used to determine niacinamide content in tablet cores. A 3-level, 2-factor full factorial design was utilized to generate a partial least-squares model for active pharmaceutical ingredient quantification. Validation of the transmission Raman model was focused on figures of merit from three independent batches manufactured at pilot scale. The resultant model statistics were evaluated along with the linearity, accuracy, precision and robustness assessments. Method specificity was demonstrated by accurate determination of niacinamide in the presence of niacin (an expected related substance). The method was demonstrated as fit for purpose and had the desirable characteristics of very short analysis times (∼2.5s per tablet). The resulting method was used for routine content uniformity analysis of single dosage units in a stability study.
Keywords: Transmission Raman spectroscopy; Validation; ICH-Q2; Stability-indicating assay;

Topical delivery of aqueous micellar resolvin E1 analog (RX-10045) by Kishore Cholkar; Brian C. Gilger; Ashim K. Mitra (326-334).
Display OmittedThe primary objective of this study were to optimize aqueous micellar solution of isopropyl ester prodrug of resolvin (RX-10045), study in vivo ocular compatibility and tissue distribution following topical administration.An optimized ratio of hydrogenated castor-oil and octoxynol-40 (1.0:0.05 wt%) was prepared to entrap RX-10045 in the hydrophobic core of micelles. RX-10045 aqueous micelles were subjected to characterization. In vitro stability studies were performed at 4 °C, 25 °C and 40 °C. In vivo studies were conducted in New Zealand albino rabbits following topical drop administration.Aqueous RX-10045 micellar solutions were successfully prepared. Micelles had a mean diameter of ∼12 nm with low negative surface charge. RX-10045 demonstrated high stability in citrate buffer (0.01 M) at 40 °C. Hackett–McDonald ocular irritation scores were extremely low comparable to negative control. No significant difference in intraocular pressure was noted. Electroretinography studies did not reveal any retinal damage after multiple dosing of RX-10045 micellar solution. Ocular tissue distribution studies demonstrated appreciable drug concentrations in anterior ocular tissues. Moreover, RX-10008 (active metabolite of RX-10045) was detected in retina/choroid upon topical drop instillation.A clear, stable, aqueous 0.1% RX-10045 micellar formulation was successfully prepared. Micellar solution was well-tolerated and did not have any measurable tissue damage in rabbit ocular tissues. Micelles appear to follow conjunctival/scleral pathway to reach back-of-the-eye tissue (retina). Topical aqueous formulations may be employed to treat posterior ocular diseases. Such micellar topical formulations may be more patient acceptable over invasive routes of administrations such as intravitreal injection/implants.
Keywords: Aqueous; Formulation; Micelles; Resolving; Inflammation; Sclera; Drug delivery; Back-of-the-eye; Posterior; Topical; Eye drop; Retina/choroid; Rabbits;

Mutual sensitization mechanism and self-degradation property of drug delivery system for in vitro photodynamic therapy by Yi Ding; Lin Zhou; Xin Chen; Qi Wu; Ziyi Song; Shaohua Wei; Jiahong Zhou; Jian Shen (335-346).
Photosensitizer and TiO2 were co-loaded on graphene oxide to be used as drug delivery system. The system has mutual sensitization mechanism to generate more reactive oxygen species than free photosensitizer, and therefore, improve its phototoxicity to cancer cells. Interestingly, the system can be self-degraded after photodynamic process.Display OmittedIn this manuscript, a photosensitive anti-cancer drug, hypocrellin A (HA), and TiO2 nanoparticles were co-loaded on the surface of graphene oxide (GO) as a photosensitive drug delivery system. In vitro studies have demonstrated the active uptake of the system into the mitochondrial of tumor cells. Such system has mutual sensitization mechanism to greatly improve the reactive oxygen species (ROSs) generation ability of the complex by visible light irradiation and, thereby, the strong photodynamic therapy (PDT) efficacy. Furthermore, during such PDT process, GO can be destroyed by the ROSs, which would helpful for the metabolism of this drug delivery system.
Keywords: Hypocrellin A; Graphene oxide; TiO2; Cancer; Mutual sensitization; Self-degradation;

Display OmittedPurpose of this study was to investigate the ability of octenyl succinic anhydride (OSA) starch as emulsifier and solid carrier in dry emulsion (DE) and dry suspension (DS) formulations. Fenofibrate (FF) was loaded at lower and higher than its saturation concentration in oil phase to prepare the DE and DS by spray drying method. The DE and DS were successfully prepared with 36–48% and 46% production yield, respectively. After reconstitution in water, the emulsion with mean droplet size of 1–2 μm was obtained. Solid state characterization revealed the amorphous state of FF and the crystalline state of OSA starch in both DE and DS formulations. Both DE and DS enhanced FF dissolution rate compared to pure material and DS showed the highest dissolution rate. The DE and DS could be compressed to the tablets with acceptable disintegration time and without changeable dissolution profile. Moreover, the dissolution profiles of both DE and DS remained unchanged after 2 months storage at 40 °C.
Keywords: Octenyl succinic anhydride starch; Emulsifying agent; Solid carrier; Dry emulsion; Spray drying; Fenofibrate;

Investigation of surface porosity measurements and compaction pressure as means to ensure consistent contact angle determinations by René Holm; Simon Borkenfelt; Morten Allesø; Jens Enevold Thaulov Andersen; Stefania Beato; Per Holm (355-361).
Display OmittedCompounds wettability is critical for a number of central processes including disintegration, dispersion, solubilisation and dissolution. It is therefore an important optimisation parameter both in drug discovery but also as guidance for formulation selection and optimisation. Wettability for a compound is determined by its contact angle to a liquid, which in the present study was measured using the sessile drop method applied to a disc compact of the compound. Precise determination of the contact angle is important should it be used to either rank compounds or selected excipients to e.g. increase the wetting from a solid dosage form. Since surface roughness of the compact has been suggested to influence the measurement this study investigated if the surface quality, in terms of surface porosity, had an influence on the measured contact angle. A correlation to surface porosity was observed, however for six out of seven compounds similar results were obtained by applying a standard pressure (866 MPa) to the discs in their preparation. The data presented in the present work therefore suggest that a constant high pressure should be sufficient for most compounds when determining the contact angle. Only for special cases where compounds have poor compressibility would there be a need for a surface-quality-control step before the contact angle determination.
Keywords: Wettability; Sessile drop; Surface roughness; Surface porosity;