International Journal of Pharmaceutics (v.487, #1-2)
EDITORIAL BOARD (iii).
Ibuprofen-in-cyclodextrin-in-W/O/W emulsion – Improving the initial and long-term encapsulation efficiency of a model active ingredient by Magnus N. Hattrem; Kåre A. Kristiansen; Finn L. Aachmann; Morten J. Dille; Kurt I. Draget (1-7).
Display OmittedA challenge in formulating water-in-oil-in-water (W/O/W) emulsions is the uncontrolled release of the encapsulated compound prior to application. Pharmaceuticals and nutraceuticals usually have amphipathic nature, which may contribute to leakage of the active ingredient. In the present study, cyclodextrins (CyDs) were used to impart a change in the relative polarity and size of a model compound (ibuprofen) by the formation of inclusion complexes. Various inclusion complexes (2-hydroxypropyl (HP)-β-CyD-, α-CyD- and γ-CyD-ibuprofen) were prepared and presented within W/O/W emulsions, and the initial and long-term encapsulation efficiency was investigated. HP-β-CyD-ibuprofen provided the highest encapsulation of ibuprofen in comparison to a W/O/W emulsion with unassociated ibuprofen confined within the inner water phase, with a four-fold increase in the encapsulation efficiency. An improved, although lower, encapsulation efficiency was obtained for the inclusion complex γ-CyD-ibuprofen in comparison to HP-β-CyD-ibuprofen, whereas α-CyD-ibuprofen had a similar encapsulation efficiency to that of unassociated ibuprofen. The lower encapsulation efficiency of ibuprofen in combination with α-CyD and γ-CyD was attributed to a lower association constant for the γ-CyD-ibuprofen inclusion complex and the ability of α-CyD to form inclusion complexes with fatty acids. For the W/O/W emulsion prepared with HP-β-CyD-ibuprofen, the highest encapsulation of ibuprofen was obtained at hyper- and iso-osmotic conditions and by using an excess molar ratio of CyD to ibuprofen. In the last part of the study, it was suggested that the chemical modification of the HP-β-CyD molecule did not influence the encapsulation of ibuprofen, as a similar encapsulation efficiency was obtained for an inclusion complex prepared with mono-1-glucose-β-CyD.
Keywords: Cyclodextrin; W/O/W emulsion; Inclusion complex; Encapsulation; Drug delivery;
MPEG-DSPE polymeric micelle for translymphatic chemotherapy of lymph node metastasis by Xue Li; Qing Dong; Zhiqiang Yan; Weiyue Lu; Lingling Feng; Cao Xie; Zuoxu Xie; Bingxia Su; Min Liu (8-16).
Display OmittedLymph node metastasis is one of the major pathways for tumor formation and it is difficult to deliver chemotherapeutics at therapeutic concentrations to lymph node metastasis. This study prepared methyl poly(ethylene glycol)-distearoylphosphatidylethanolamine/doxorubicin (MPEG-DSPE/DOX) micelle for the treatment of lymph node metastasis. The MPEG-DSPE/DOX micelle prepared were of spherical morphology with a particle size of 20 ± 5 nm. The uptake rates of DOX and MPEG-DSPE/DOX micelle by A375 cells were 51.2% and 88.7%, respectively. The phagocytosis rate of MPEG-DSPE/Rhodamine B micelle by RAW264.7 cells was 17.2-fold lower than for Rhodamine B alone. After subcutaneous injection, MPEG-DSPE micelle underwent lymphatic absorption and accumulated in popliteal lymph nodes. MPEG-DSPE/DOX micelle significantly alleviated damage to the subcutaneous tissue of the injection sites compared with DOX alone. We established a model of nude mice bearing lymph node metastasis of A375 cells. After subcutaneous injection, the weights of both the popliteal and iliac lymph nodes of the MPEG-DSPE/DOX micelle group were significantly lower than in the saline and DOX groups. MPEG-DSPE/DOX micelle effectively killed the tumor cells in popliteal and iliac lymph nodes. In conclusion, MPEG-DSPE micelle is a promising drug delivery system for the treatment of lymph node metastasis.
Keywords: Lymph node; Metastasis; MPEG-DSPE; Polymeric micelle;
Optimized mixed oils remarkably reduce the amount of surfactants in microemulsions without affecting oral bioavailability of ibuprofen by simultaneously enlarging microemulsion areas and enhancing drug solubility by Yizhen Chen; Jue Tuo; Huizhi Huang; Dan Liu; Xiuhua You; Jialuo Mai; Jiaqi Song; Yanqi Xie; Chuanbin Wu; Haiyan Hu (17-24).
Display OmittedThe toxicity and irritation associated with high amounts of surfactants restrict the extensive utilization of microemulsions. To address these shortcomings, employing mixed oils to enlarge microemulsion areas therefore reducing surfactant contents is a promising strategy. However, what kinds of mixed oils are more efficient in enlarging microemulsion areas still remains unclear. In this research, we found that the chain length and degree of unsaturation of oils play a key role in enlarging microemulsion areas. The combination of moderate chain saturated oil caprylic/capric triglyceride (GTCC) with long chain unsaturated oil glycerol trioleate significantly increased the microemulsion areas. Solubility of ibuprofen in the mixed oils was unexpectedly and remarkably increased (almost 300 mg/mL) compared with that (around 100 mg/mL) of the single oil (GTCC), which also resulted in greatly increased solubility of ibuprofen in mixed oils-containing microemulsions. By optimizing the mixed oil formulation, the absolute amount of surfactant in drug-loaded microemulsions was reduced but increased drug oral bioavailability in rats was maintained. It could be concluded that the combined use of moderate chain oils and long chain unsaturated oils could not only acquire enlarged microemulsion areas but also enhanced drug solubility, therefore doubly reducing surfactant amount, which is extremely beneficial for developing safe microemulsions.
Keywords: Mixed oils; Chain length; Unsaturated degrees; Microemulsion areas; Drug solubility; Oral bioavailability;
Self-nanoemulsifying drug delivery systems as novel approach for pDNA drug delivery by Sabine Hauptstein; Felix Prüfert; Andreas Bernkop-Schnürch (25-31).
Display OmittedIt was the aim of this study to investigate a novel strategy for oral gene delivery utilizing a self-nanoemulsifying drug delivery system (SNEDDS). After hydrophobic ion pairing a plasmid was incorporated into SNEDDS. The mean droplet size of resulting nanoemulsions was determined to be between 45.8 and 47.5 nm. A concentration dependent cytotoxicity of the formulations was found on HEK-293 cells via MTT assay. Degradation studies via DNase I showed that incorporation into SNEDDS led to significantly, up to 8-fold prolonged resistant time against enzymatic digestion compared to naked pDNA and pDNA–lipid complexes. Transfection studies carried out revealed a significantly improved transfection compared to naked pDNA. Further, no decrease in transfection efficiency compared to transfection using Lipofectin® transfection reagent was observed.
Keywords: SNEDDS; Nonviral vector; Hydrophobic ion pairing; Gene delivery;
DEM analysis of the effect of particle–wall impact on the dispersion performance in carrier-based dry powder inhalers by Jiecheng Yang; Chuan-Yu Wu; Michael Adams (32-38).
Display OmittedThe impact between particles or agglomerates and a device wall is considered as an important mechanism controlling the dispersion of active pharmaceutical ingredient (API) particles in dry powder inhalers (DPIs). In order to characterise the influencing factors and better understand the impact induced dispersion process for carrier-based DPIs, the impact behaviour between an agglomerate and a wall is systematically investigated using the discrete element method. In this study, a carrier-based agglomerate is initially formed and then allowed to impact with a target wall. The effects of impact velocity, impact angle and work of adhesion on the dispersion performance are analysed. It is shown that API particles in the near-wall regions are more likely to be dispersed due to the deceleration of the carrier particle resulted from the impact with the wall. It is also revealed that the dispersion ratio increases with increasing impact velocity and impact angle, indicating that the normal component of the impact velocity plays a dominant role on the dispersion. Furthermore, the impact induced dispersion performance for carrier-based DPI formulations can be well approximated using a cumulative Weibull distribution function that is governed by the ratio of overall impact energy and adhesion energy.
Keywords: Impact; Adhesion; Dispersion; Discrete element method; Dry powder inhalation;
Electrophoretic mobility as a tool to separate immune adjuvant saponins from Quillaja saponaria Molina by Roger Gilabert-Oriol; Alexander Weng; Benedicta von Mallinckrodt; Anja Stöshel; Linda Nissi; Matthias F. Melzig; Hendrik Fuchs; Mayank Thakur (39-48).
Display Omitted Quillaja saponins are used as adjuvants in animal vaccines but their application in human vaccination is still under investigation. Isolation and characterization of adjuvant saponins is very tedious. Furthermore, standardization of Quillaja saponins is critical pertaining to its application in humans. In this study, a convenient method based on agarose gel electrophoresis was developed for the separation of Quillaja saponins. Six different commercial Quillaja saponins were segregated by size/charge into numerous fractions. Each of the fractions was characterized by ESI-TOF-MS spectroscopy and thin layer chromatography. Real-time impedance-based monitoring and red blood cell lysis assay were used to evaluate cytotoxicity and hemolytic activities respectively. Two specific regions in the agarose gel (delimited by specific relative electrophoretic mobility values) were identified and characterized by exclusive migration of acylated saponins known to possess immune adjuvant properties (0.18–0.58), and cytotoxic and hemolytic saponins (0.18–0.94). In vivo experiments in mice with the isolated fractions for evaluation of adjuvant activity also correlated with the relative electrophoretic mobility. In addition to the separation of specific Quillaja saponins with adjuvant effects as a pre-purification step to HPLC, agarose gel electrophoresis stands out as a new method for rapid screening, separation and quality control of saponins.
Keywords: Electrophoresis; Quillaja saponins; Cytotoxicity; Hemolysis; Immune adjuvant;
Development of drug-in-adhesive patch formulations for transdermal delivery of fluoxetine: In vitro and in vivo evaluations by Eunjae Jung; Eun Young Lee; Hoo-Kyun Choi; Sang-Jun Ban; Seung-Hyuk Choi; Jung Sun Kim; In-Soo Yoon; Dae-DuK Kim (49-55).
Display OmittedThe aim of this study was to develop drug-in adhesive (DIA) patch formulations for the transdermal delivery of fluoxetine (FX). The DIA patch formulations containing FX were prepared and optimized with various pressure sensitive adhesives, drug contents and enhancers. Among the various formulations, DuroTak 87-502B-based patch formulation containing 20% (w/w) FX with no enhancer was selected for in vivo pharmacokinetic study based on in vitro permeation studies using hairless mouse, rat and human cadaver skins. The C max of FX after the transdermal administration of the optimized patch formulation in rats was 52.38 ng/ml, and plasma concentration of FX was maintained for 36 h. Moreover, the predicted human C ss (55.79 ng/ml) and C max (27.35 ng/ml) were in good agreement with the reported plasma levels (15–55 ng/ml) of oral FX in clinical applications. These results suggest that the optimized patch formulation could be further developed for clinical applications, providing the therapeutic plasma level of FX over an extended period. To the best of our knowledge, our results are the first reported in vitro and in vivo data on the preparation and optimization of FX-loaded DIA patch, showing its feasibility as an effective transdermal delivery system for FX.
Keywords: Fluoxetine; Transdermal delivery; Drug-in-adhesive; Patch; Pharmacokinetics;
Self-emulsifying drug delivery system developed by the HLB-RSM approach: Characterization by transmission electron microscopy and pharmacokinetic study by Badr Bahloul; Mohamed Ali Lassoued; Johanne Seguin; René Lai-Kuen; Hélène Dhotel; Souad Sfar; Nathalie Mignet (56-63).
Display OmittedRecently, we developed a new approach to rationalize an optimized design for self-emulsifying drug delivery system (SEDDS) by introducing the HLB and the response surface as determinant factors in SEDDS development. The aim of this current paper is to assess the suitability of this HLB-RSM approach to enhance the oral bioavailability of BCS class II compounds using fenofibrate as drug model. Eight SEDDS formulations (I → VIII) were pre-selected regarding their self-emulsification capacity and their effect on increasing in vitro drug release. They were firstly evaluated for their thermodynamic stability and zeta potential. Unstable SEDDS were discarded meanwhile the structural morphology of the stable ones (I, VI and VIII) was characterized using transmission electron microscopy (TEM). A pharmacokinetic study was then undertaken on male BALB/cJRj mices. The in vivo results showed a significant increase of fenofibrate absorption for all the three stable SEDDS formulations compared to the commercialized form, (LIPANTHYL micronized® (p < 0.05)). The highest enhancement was recorded for SEDDS I, where AUC and C max values respectively increased by 2 and 4.4 folds. This justifies the fact that HLB-RSM approach could be considered as a promising method for the development of efficient and highly stable SEDDS aiming to increase the poor bioavailability of BCS class II molecules.
Keywords: Self emulsifying drug delivery systems; HLB-RSM approach; Pharmacokinetics; Transmission electron microscopy;
Development of fluorous lipid-based nanobubbles for efficiently containing perfluoropropane by Yusuke Oda; Ryo Suzuki; Tatsuya Mori; Hideyo Takahashi; Hideaki Natsugari; Daiki Omata; Johan Unga; Hitoshi Uruga; Mutsumi Sugii; Shigeru Kawakami; Yuriko Higuchi; Fumiyoshi Yamashita; Mitsuru Hashida; Kazuo Maruyama (64-71).
Display OmittedNano-/microbubbles are expected not only to function as ultrasound contrast agents but also as ultrasound-triggered enhancers in gene and drug delivery. Notably, nanobubbles have the ability to pass through tumor vasculature and achieve passive tumor targeting. Thus, nanobubbles would be an attractive tool for use as ultrasound-mediated cancer theranostics. However, the amounts of gas carried by nanobubbles are generally lower than those carried by microbubbles because nanobubbles have inherently smaller volumes. In order to reduce the injection volume and to increase echogenicity, it is important to develop nanobubbles with higher gas content. In this study, we prepared 5 kinds of fluoro-lipids and used these reagents as surfactants to generate “Bubble liposomes”, that is, liposomes that encapsulate nanobubbles such that the lipids serve as stabilizers between the fluorous gas and water phases. Bubble liposome containing 1-stearoyl-2-(18,18-difluoro)stearoyl-sn-glycero-3-phosphocholine carried 2-fold higher amounts of C3F8 compared to unmodified Bubble liposome. The modified Bubble liposome also exhibited increased echogenicity by ultrasonography. These results demonstrated that the inclusion of fluoro-lipid is a promising tool for generating nanobubbles with increased efficiency of fluorous gas carrier.
Keywords: Nanobubbles; Ultrasound imaging; Fluorous chemistry; Echogenicity;
Continuous twin screw melt granulation of glyceryl behenate: Development of controlled release tramadol hydrochloride tablets for improved safety by Justin M. Keen; Connor J. Foley; Justin R. Hughey; Ryan C. Bennett; Vincent Jannin; Yvonne Rosiaux; Delphine Marchaud; James W. McGinity (72-80).
Display OmittedInterest in granulation processes using twin screw extrusion machines is rapidly growing. The primary objectives of this study were to develop a continuous granulation process for direct production of granules using this technique with glyceryl behenate as a binder, evaluate the properties of the resulting granules and develop controlled release tablets containing tramadol HCl. In addition, the granulation mechanism was probed and the polymorphic form of the lipid and drug release rate were evaluated on stability. Granules were prepared using a Leistritz NANO16 twin screw extruder operated without a constricting die. The solid state of the granules were characterized by differential scanning calorimetry and X-ray diffraction. Formulated tablets were studied in 0.1 N HCl containing 0–40% ethanol to investigate propensity for alcohol induced dose dumping. The extrusion barrel temperature profile and feed rate were determined to be the primary factors influencing the particle size distribution. Granules were formed by a combination immersion/distribution mechanism, did not require subsequent milling, and were observed to contain desirable polymorphic forms of glyceryl behenate. Drug release from tablets was complete and controlled over 16 h and the tablets were determined to be resistant to alcohol induced dose dumping. The drug release rate from the tablets was found to be stable at 40 °C and 75% relative humidity for the duration of a 3 month study.
Keywords: Melt granulation; Twin screw granulation; Dose dumping; Controlled release;
Herceptin conjugated PLGA-PHis-PEG pH sensitive nanoparticles for targeted and controlled drug delivery by Zilan Zhou; Apurva Badkas; Max Stevenson; Joo-Youp Lee; Yuet-Kin Leung (81-90).
Display OmittedA dual functional nano-scaled drug carrier, comprising of a targeting ligand and pH sensitivity, has been made in order to increase the specificity and efficacy of the drug delivery system. The nanoparticles are made of a tri-block copolymer, poly(d,l lactide-co-glycolide) (PLGA)-b-poly(l-histidine) (PHis)-b-polyethylene glycol (PEG), via nano-precipitation. To provide the nanoparticle feature of endolysosomal escape and pH sensitivity, poly(l-histidine) was chosen as a proton sponge polymer. Herceptin, which specifically binds to HER2 antigen, was conjugated to the nanoparticles through click chemistry. The nanoparticles were characterized via dynamic light scattering (DLS) and transmission electron microscopy (TEM). Both methods showed the sizes of about 100 nm with a uniform size distribution. The pH sensitivity was assessed by drug releases and size changes at different pH conditions. As pH decreased from 7.4 to 5.2, the drug release rate accelerated and the size significantly increased. During in vitro tests against human breast cancer cell lines, MCF-7 and SK-BR-3 showed significantly increased uptake for Herceptin-conjugated nanoparticles, as compared to non-targeted nanoparticles. Herceptin-conjugated pH-sensitive nanoparticles showed the highest therapeutic effect, and thus validated the efficacy of a combined approach of pH sensitivity and active targeting.
Keywords: Polymeric nanoparticles; Breast cancer; Active targeting; pH sensitivity; Herceptin®;
Microheterogeneity in frozen protein solutions by Alan Twomey; Kosaku Kurata; Yutaka Nagare; Hiroshi Takamatsu; Alptekin Aksan (91-100).
Display OmittedIn frozen and lyophilized systems, the biological to be stabilized (e.g. therapeutic protein, biomarker, drug-delivery vesicle) and the cryo-/lyo-protectant should be co-localized for successful stabilization. During freezing and drying, many factors cause physical separation of the biological from the cryo-/lyo-protectant, called microheterogeneity (MH), which may result in poor stabilization efficiency. We have developed a novel technique that utilized confocal Raman microspectroscopy in combination with counter-gradient freezing to evaluate the effect of a wide range of freezing temperatures (−20 < T F < 0 °C) on the MH generated within a frozen formulation in only a few experiments. The freezing experiments conducted with a model system (albumin and trehalose) showed the presence of different degrees of MH in the freeze-concentrated liquid (FCL) in all solutions tested. Mainly, albumin tended to accumulate near the ice interface, where it was physically separated from the cryoprotectant. In frozen 10 wt% trehalose solutions, heterogeneity in FCL was relatively low at any T F. In frozen 20 wt% trehalose solutions, the optimum albumin to trehalose ratio in the FCL can only be ensured if the solution was frozen within a narrow range of temperatures (−16 < T F < −10 °C). In the 30 wt% trehalose solutions, freezing within a much more narrow range (−12 < T F < −10 °C) was needed to ensure a fairly homogeneous FCL. The method developed here will be helpful for the development of uniformly frozen and stable formulations and freezing protocols for biological as MH is presumed to directly impact stability.
An in-vitro–in-vivo model for the transdermal delivery of cholecalciferol for the purposes of rodent management by J. Davies; A. Ingham (101-109).
Display OmittedThe natural selection of anticoagulant resistant rats has resulted in a need for an alternative to anticoagulant rodenticides which differs in both active ingredient and in the method of dosing.Cholecalciferol toxicity to rodents using the dermal route is demonstrated using a variety of penetration enhancing formulations in two in-vitro models and finally in-vivo.A 1 ml dose of 50/50 (v/v) DMSO/ethanol containing 15% (v/v) PEG 200 and 20% (w/v) cholecalciferol was judged as ‘sufficiently effective’ in line with the European Union’s Biocidal Products Regulation (No. 528/2012) during in-vivo studies. This dose was found to cause 100% mortality in a rat population in 64.4 h (±22 h).
Keywords: Cholecalciferol; Transdermal; Rodenticide; BPR; Regulation No. 528/2012; Efficacy;
Controlled delivery of valsartan by cross-linked polymeric matrices: Synthesis, in vitro and in vivo evaluation by Muhammad Sohail; Mahmood Ahmad; Muhammad Usman Minhas; Liaqat Ali; Ikrima Khalid; Haroon Rashid (110-119).
Display OmittedThe purpose of study was to develop chemically cross-linked chitosan-co-poly(AMPS) hydrogel based on low molecular weight chitosan for pH-responsive and controlled drug delivery of a model drug. Cross-linking was achieved chemically, by using free radical polymerization technique. Polymer (low molecular weight chitosan) was chemically cross-linked with monomer (2-acrylamido-2-methylpropane sulfonic acid) in aqueous medium. N, N′-Methylenebisacrylamide (MBA) was used as cross-linking agent. Sodium hydrogen sulfite (SHS) and ammonium peroxodisulphate (APS) were used as initiators in a chemical reaction. Hydrogels were characterized by FT-IR, SEM and DSC. Swelling studies and pH-sensitivity of hydrogels were studies at pH 1.2 and 7.4. Chitosan-co-poly(AMPS) hydrogels were administered to rabbits orally to evaluate its pharmacokinetic behavior. As a result of successful cross-linking of polymer and monomer, novel co-polymer has been developed, having suitable characteristics as desired for controlled release drug delivery system. Maximum swelling, drug loading and release have been observed at pH 7.4. In vivo results exhibited significant drug release and absorption at pH 7.4 in rabbits. It is concluded that highly swelling chitosan-AMPS based hydrogels were developed having pH independent swelling and pH dependent drug release properties. These hydrogels have great potential to be used for loading and controlled release of various therapeutic agents.
Keywords: Chitosan; AMPS; Hydrogel; Crosslinking; Polymeric matrices; Controlled release; Drug delivery; Valsartan;
Tris-biphenyl triazine, a new ultraviolet filter studied in terms of photoprotective efficacy by C Couteau; E. Paparis; C. Chauvet; L. Coiffard (120-123).
Display OmittedThere are relatively few authorized ultraviolet filters in Europe and this presents a certain number of problems when we want to formulate a sun protection product which both ensures a high level of protection and respects the recommendations in force in terms of broad-spectrum efficacy, with, in particular, a critical wavelength (λ c) greater than or equal to 370 nm. A new ultraviolet filter has just been launched on the market. Known as tris-biphenyl triazine, it is the first filter to be registered on Annexe VI of “Cosmetics Regulation” (EC) No. 1223/2009 of the European Parliament and of the Council, which gives a list of the ultraviolet filters allowed in cosmetic products, since the regulation came into force in July 2013. This filter is both very effective (as it enables 2 SPF units and 1 UVA-PF units to be obtained respectively, by percentage of use) and very photostable (since the SPF and UVA-PF do not vary after 2 h of irradiation in a solar simulator). Its broad spectrum associated with its qualities in terms of efficacy and photostability make it a choice ingredient for the formulation of sun protection products.
Keywords: Tris-biphenyl triazine; UVA-II; Efficacy; Photostability;
Twin screw wet granulation: Binder delivery by Mohammed F. Saleh; Ranjit M. Dhenge; James J. Cartwright; Michael J. Hounslow; Agba D. Salman (124-134).
Display OmittedThe effects of three ways of binder delivery into the twin screw granulator (TSG) on the residence time, torque, properties of granules (size, shape, strength) and binder distribution were studied. The binder distribution was visualised through the transparent barrel using high speed imaging as well as quantified using offline technique. Furthermore, the effect of binder delivery and the change of screw configuration (conveying elements only and conveying elements with kneading elements) on the surface velocity of granules across the screw channel were investigated using particle image velocimetry (PIV). The binder was delivered in three ways; all solid binder incorporated with powder mixture, 50% of solid binder mixed with powder mixture and 50% mixed with water, all the solid binder dissolved in water. Incorporation of all solid binder with powder mixture resulted in the relatively longer residence time and higher torque, narrower granule size distribution, more spherical granules, weaker big-sized granules, stronger small-sized granules and better binder distribution compared to that in other two ways. The surface velocity of granules showed variation from one screw to another as a result of uneven liquid distribution as well as shown a reduction while introducing the kneading elements into the screw configuration.
Keywords: Twin screw; Wet granulation; Granule properties; Online binder distribution; PIV;
Propranolol hydrochloride-loaded liposomal gel for transdermal delivery: Characterization and in vivo evaluation by Yuanyuan Guan; Tiantian Zuo; Minglu Chang; Fang Zhang; Ting Wei; Wei Shao; Guimei Lin (135-141).
Display OmittedThis study was to develop propranolol hydrochloride (PRO)-loaded liposomal gel as a topical drug delivery system. Scanning electron microscope (SEM) revealed that the liposomes were spherical and scattered in the surface of the gel. Pseudoplastic flows of PRO liposomal gel were showed after stored at three different temperatures. Besides, PRO liposomal gel showed non-irritating to the skin of rabbit. Skin deposition studies in vivo demonstrated that PRO liposomal gel can apparently increase drug content in skin compared with PRO gel. Histopathology examination showed that PRO liposomal gel could obviously weaken the barrier function of stratum corneum (SC) by comparison with PRO gel. What is more, the plasma pharmacokinetic showed the maximum concentration in plasma was 0.41 μg/mL and 1.17 μg/mL after topical and oral administration respectively. However, tissue distribution study showed PRO liposomal gel obviously changed drug distribution in tissues, significantly increased drug concentration in skin with about 74 folds compared with PRO gel. In conclusion, liposomes-based gel could be a promising vehicle as a transdermal delivery system of PRO.
Keywords: Propranolol hydrochloride; Liposomal gel; Transdermal delivery; Pharmacokinetic; Tissue distribution;
Slow-release of famotidine from tablets consisting of chitosan/sulfobutyl ether β-cyclodextrin composites by Makoto Anraku; Ayumu Hiraga; Daisuke Iohara; James D. Pipkin; Kaneto Uekama; Fumitoshi Hirayama (142-147).
Display OmittedAn intermolecular complex formed from a 1:1 weight ratio of chitosan (CS, molecular weight 30 kDa) and sulfobutyl ether β-cyclodextrin (SBE-β-CyD, degree of substitution 7) was less soluble than either of the original components. The release of famotidine from tablets composed of a simple mixture of CS and SBE-β-CyD is slower in media at pH 1.2 than at 6.8. Macroscopic observation of tablets and a kinetic analysis of release profiles suggested that, at pH 1.2, the drug was slowly released from the less-soluble CS/SBE-β-CyD complex formed on the surface of the tablet immediately after exposure to water, accompanied by the dissolution of the interpolymer complex and, ultimately, the erosion and disintegration of the tablet. In the case of the medium at pH 6.8, the formation of a gel by CS was the cause of the slow release, especially for CS/SBE-β-CyD tablets which were significantly gelated and both the diameter and thickness of the tablet had expanded. The in vitro slow releasing characteristic of the CS/SBE-β-CyD tablet was reflected in the in vivo absorption of the drug after oral administration to rats. These results suggest that a simple mixing of CS and SBE-β-CyD is potentially useful for the controlled release of a drug.
Keywords: Chitosan; Sulfobutyl ether β-cyclodextrin; Famotidine; Interpolymer complex; Release control; Extending release;
Transcutaneous delivery of leflunomide nanoemulgel: Mechanistic investigation into physicomechanical characteristics, in vitro anti-psoriatic and anti-melanoma activity by Swati Pund; Satish Pawar; Shashikant Gangurde; Deepali Divate (148-156).
Display OmittedThe present study is a mechanistic validation of ‘proof of concept’ of effective topical delivery of leflunomide (LFD) nanoemulgel for localized efficient treatment of psoriatic lesions as well as melanoma affected skin regions. Hyperproliferation of keratinocytes in psoriasis and symbiotic relationship between keratinocytes and melanocytes, justifies the need of dual acting treatment. LFD is recently introduced significantly effective disease modifying anti-rheumatic drug and has been considered valuable for the treatment of psoriatic arthritis as well as melanoma. Current available treatments for psoriasis and melanoma are inefficient due to systemic side effects, poor transcutaneous permeation and thus present a challenge for development of novel colloidal carriers. We newly reformulated LFD as a nanoemulgel based on self nanoemulsifying technique using Capryol 90, Cremophor EL, Transcutol HP as nanoemulsifying components and Pluronic F127 as a gelling agent. This thermodynamically stable nanoemuslsifying preconcentrate after gelation showed mean globule size, 123.7 nm and viscosity 9620 ± 93 cp. Complete mechanical characterization was carried out using Texture Analyzer and hardness, adhesiveness and springiness index were found to be 523 gms, 431 gms and 1.02, respectively. Ex vivo permeation through rat abdominal skin revealed significant improvement in flux, apparent permeability coefficient, steady state diffusion coefficient and drug deposition in skin due to nanoemulsification of LFD. The in vitro cytoxicity of LFD nanoemulgel in human HaCaT, melanoma A375 and SK-MEL-2 cell lines showed significantly enhanced therapeutic response. In gist, LFD nanoemulgel for trancutaneous delivery will reduce the overall dose and drug consumption, by effectively localizing at the applied target site and will ultimately minimize systemic side effects.
Keywords: Leflunomide; Nanoemulgel; Ex vivo permeation; Texture profile analysis; Psoriasis; Melanoma;
Marker-ion analysis for quantification of mucoadhesivity of microparticles in particle-retention assays by Daniel Preisig; Michael Weingartner; Felipe J.O. Varum; Roberto Bravo; Rainer Alles; Jörg Huwyler; Maxim Puchkov (157-166).
Display OmittedThe objective of the present work was to develop an improved method to quantify particle retention on mucosal tissue under dynamic flow conditions with simultaneous determination of drug dissolution. The principle was to dissolve the collected inert carrier material and quantify specific marker ions by reliable analytical methods. The mucoadhesive model particles consisted of drug-loaded porous calcium carbonate microcarriers coated with chitosan, and quantification of calcium ions by capillary electrophoresis enabled to determine particle-retention kinetics on colonic mucosal tissue. The method was validated by image analysis, and the particle-retention assay was successfully applied to granulate material (125–250 mm) and small particles (<90 μm) with mucoadhesive properties. Particle retention on colonic mucosa was improved by increasing the chitosan content, demonstrating the sensitivity and usefulness of marker-ion analysis for quantification of detached particles. Furthermore, we showed that drug dissolution from mucoadhesive microparticles followed comparable kinetics in the particle-retention assay and the standard USP IV method. Our findings are helpful for the development of micro-sized colonic drug delivery systems, in particular for optimization of mucoadhesive properties and sustained drug release kinetics of porous drug carriers.
Keywords: Mucoadhesion; Bioadhesion; Microparticles; Particle-retention assay; Marker-ion analysis; Colon delivery;
Development of taste masked caffeine citrate formulations utilizing hot melt extrusion technology and in vitro–in vivo evaluations by Manjeet B. Pimparade; Joseph T. Morott; Jun-Bom Park; Vijay I. Kulkarni; Soumyajit Majumdar; S.N. Murthy; Zhuoyang Lian; Elanor Pinto; Vivian Bi; Thomas Durig; Reena Murthy; Shivakumar H.N; K. Vanaja; C. Kumar P; Michael A. Repka (167-176).
Display OmittedThe objective of this study was to develop caffeine citrate orally disintegrating tablet (ODT) formulations utilizing hot-melt extrusion technology and evaluate the ability of the formulation composition to mask the unpleasant bitter taste of the drug using in vitro and in vivo methods. Ethylcellulose, along with a suitable plasticizer, was used as a polymeric carrier. Pore forming agents were incorporated into the extruded matrix to enhance drug release. A modified screw configuration was applied to improve the extrusion processability and to preserve the crystallinity of the API. The milled extrudates were subjected to dissolution testing in an artificial salivary fluid and investigations using e-tongue, to assess the extent of masking of bitter taste of the API. There was an insignificant amount of drug released from the formulation in the salivary medium while over 80% of drug released within 30 min in 0.1 N HCl. ODTs were also developed with the extrudate mixed with mannitol and crospovidone. The quality properties such as friability and disintegration time of the ODTs met the USP specifications. The lead extrudate formulations and the ODTs prepared using this formulation were subjected to human gustatory evaluation. The formulations were found to mask the unpleasant taste of caffeine citrate significantly.
Keywords: Hot-melt extrusion; Taste-masking; Pediatric and geriatric; Modified screw design; Ethylcellulose (EC);
A micelle-like structure of poloxamer–methotrexate conjugates as nanocarrier for methotrexate delivery by Jin Ren; Zhengjie Fang; Li Yao; Fatima Zohra Dahmani; Lifang Yin; Jianping Zhou; Jing Yao (177-186).
Display OmittedThe purpose of this study was to develop a novel featured and flexible methotrexate (MTX) formulation, in which MTX was physically entrapped and chemically conjugated in the same drug delivery system. A series of poloxamer–MTX (p–MTX) conjugates was synthesized, wherein MTX was grafted to poloxamer through an ester bond. p–MTX conjugates could self-assemble into micelle-like structures in aqueous environment and the MTX end was in the inner-core of micelles. Moreover, free MTX could be physically entrapped into p–MTX micelles hydrophobic core region to increase the total drug loading. Importantly, the resulting MTX-loaded p–MTX micelles showed a biphasic release of MTX, with a relative fast release of the entrapped MTX (about 6–7 h) followed by a sustained release of the conjugated MTX. The pharmacokinetics study showed that the mean residence time (MRT) was extended in the case of MTX-loaded p–MTX micelles, indicating a delayed MTX elimination from the bloodstream and prolonged in vivo residence time. Besides, the area under curve (AUC) of MTX-loaded p–MTX micelles was greater than free MTX, indicating a drug bioavailability improvement. Overall, MTX-loaded p–MTX micelles might be a promising nanosized drug delivery system for the cancer therapy.
Keywords: MTX; Poloxamer; Micelles; Biphasic release; Bioavailability;
Effect of liposomes on rheological and syringeability properties of hyaluronic acid hydrogels intended for local injection of drugs by Naila El Kechai; Amélie Bochot; Nicolas Huang; Yann Nguyen; Evelyne Ferrary; Florence Agnely (187-196).
Display OmittedThe aim of this work was to thoroughly study the effect of liposomes on the rheological and the syringeability properties of hyaluronic acid (HA) hydrogels intended for the local administration of drugs by injection. Whatever the characteristics of the liposomes added (neutral, positively or negatively charged, with a corona of polyethylene glycol chains, size), the viscosity and the elasticity of HA gels increased in a lipid concentration-dependent manner. Indeed, liposomes strengthened the network formed by HA chains due to their interactions with this polymer. The nature and the resulting effects of these interactions depended on liposome composition and concentration. The highest viscosity and elasticity were observed with liposomes covered by polyethylene glycol chains while neutral liposomes displayed the lowest effect. Despite their high viscosity at rest, all the formulations remained easily injectable through needles commonly used for local injections thanks to the shear-thinning behavior of HA gels. The present study demonstrates that rheological and syringeability tests are both necessary to elucidate the behavior of such systems during and post injection. In conclusion, HA liposomal gels appear to be a promising and versatile formulation platform for a wide range of applications in local drug delivery when an injection is required.
Keywords: Hyaluronic acid; Hydrogel; Liposomes; Local injection; Rheology; Syringeability;
“Pierce and inhale” design in capsule based dry powder inhalers: Effect of capsule piercing and motion on aerodynamic performance of drugs by Francesco Martinelli; Anna Giulia Balducci; Alessandra Rossi; Fabio Sonvico; Paolo Colombo; Francesca Buttini (197-204).
Display OmittedIn this work three capsule-based dry powder inhalers, available for generics product development, were compared. Two technologically different dry powder formulations were used in order to relate the capsule piercing position and motion in the device to their aerodynamic performance.A “pierce and inhale” design, in which the capsules pierced with RS01, HandiHaler or Turbospin devices were aerosolized in the same device or transferred and aerosolized with another device, was constructed and carried out.The results obtained showed that two dry powder formulations, i.e., a drug/lactose blend or a carrier-free powder, aerosolized using capsule based inhalers, performed differently. The aerosolization of drug carrier mixture in terms of drug dispersion and emitted dose, was more sensible to the piercing and device combination than the carrier free powder. The motion of the capsule during the aerosolization boosted the powder emission, whereas the powder disaggregation was more influenced by the airflow pattern around the capsule and inside the inhaler turbulence chamber.
Keywords: RS01; HandiHaler; Turbospin; Formoterol fumarate; Spray-dried insulin; Dry powder inhaler; Capsule motion;
In vitro and in vivo evaluation of Δ9-tetrahidrocannabinol/PLGA nanoparticles for cancer chemotherapy by L. Martín-Banderas; I. Muñoz-Rubio; J. Prados; J. Álvarez-Fuentes; J.M. Calderón-Montaño; M. López-Lázaro; J.L. Arias; M.C. Leiva; M.A. Holgado; M. Fernández-Arévalo (205-212).
Display OmittedNanoplatforms can optimize the efficacy and safety of chemotherapy, and thus cancer therapy. However, new approaches are encouraged in developing new nanomedicines against malignant cells. In this work, a reproducible methodology is described to prepare Δ9-tetrahidrocannabinol (Δ9-THC)-loaded poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles against lung cancer. The nanoformulation is further improved by surface functionalization with the biodegradable polymers chitosan and poly(ethylene glycol) (PEG) in order to optimize the biological fate and antitumor effect. Mean nanoparticle size (≈290 nm) increased upon coating with PEG, CS, and PEG–CS up to ≈590 nm, ≈745 nm, and ≈790 nm, respectively. Surface electrical charge was controlled by the type of polymeric coating onto the PLGA particles. Drug entrapment efficiencies (≈95%) were not affected by any of the polymeric coatings. On the opposite, the characteristic sustained (biphasic) Δ9-THC release from the particles can be accelerated or slowed down when using PEG or chitosan, respectively. Blood compatibility studies demonstrated the adequate in vivo safety margin of all of the PLGA-based nanoformulations, while protein adsorption investigations postulated the protective role of PEGylation against opsonization and plasma clearance. Cell viability studies comparing the activity of the nanoformulations against human A-549 and murine LL2 lung adenocarcinoma cells, and human embryo lung fibroblastic MRC-5 cells revealed a statistically significant selective cytotoxic effect toward the lung cancer cell lines. In addition, cytotoxicity assays in A-549 cells demonstrated the more intense anticancer activity of Δ9-THC-loaded PEGylated PLGA nanoparticles. These promising results were confirmed by in vivo studies in LL2 lung tumor-bearing immunocompetent C57BL/6 mice.
Keywords: Blood compatibility; Chitosan; Δ9-Tetrahidrocannabinol; Lung cancer; Nanoparticles; PEGylation; PLGA;
Fast releasing oral electrospun PVP/CD nanofiber mats of taste-masked meloxicam by Wipada Samprasit; Prasert Akkaramongkolporn; Tanasait Ngawhirunpat; Theerasak Rojanarata; Ruchadaporn Kaomongkolgit; Praneet Opanasopit (213-222).
Display OmittedFast release and taste masking of meloxicam (MX)-loaded polyvinylpyrrolidone (PVP)/cyclodextrin (CD) nanofiber mats were developed using an electrospinning process. CDs were blended to improve the stability of the mats. The morphology and diameter of the mats were determined using scanning electron microscopy (SEM); physical and mechanical properties were also studied. The MX content, disintegration time, MX release and cytotoxicity of the mats were investigated. In vivo studies were also performed in healthy human volunteers. The results indicated that the mats were successfully prepared with fiber in the nanometer range. MX was well incorporated into the mats, with an amorphous form. The mats showed suitable tensile strength. CDs improved the physical stability by their cage-like supramolecular structure to protect from humidity and moisture, and create bead free nanofiber mats. The nanofiber mats with CDs were physically stable without any hygroscopicity and fusion. A fast disintegration and release of MX was achieved. Moreover, this mat released MX faster than the MX powder and commercial tablets. The cytotoxicity test revealed that mats were safe for a 5-min incubation. The disintegration studies indicated that in vivo disintegration agreed with the in vitro studies; the mat rapidly disintegrated in the mouth. The less bitter of MX was occurred in the mats that incorporated CD, menthol and aspartame. In addition, this mat was physical stable for 6 months. The results suggest that these mats may be a good candidate for fast dissolving drug delivery systems of bitter drugs to increase the palatability of dosage forms.
Keywords: Nanofiber mats; Meloxicam; Taste masking; Electrospinning; Cyclodextrin;
The antitumor activity of PNA modified vinblastine cationic liposomes on Lewis lung tumor cells: In vitro and in vivo evaluation by Xue-tao Li; Mei-li He; Zhi-yan Zhou; Ying Jiang; Lan Cheng (223-233).
Display OmittedNon-small cell lung cancer (NSCLC) is one of the frequently-occurring disease in the world, and the treatment effects are usually unsatisfactory. Vinblastine is an anti-microtubule drug in clinic. In this study, a nanostructured liposome was designed and prepared for treating NSCLC. In the liposomes, peanut agglutinin (PNA) was modified on the liposomal surface, 3-(N-(N′,N′-dimethylaminoethane)carbamoyl) cholesterol was used as cationic materials, and vinblastine was encapsulated in the aqueous core of liposomes, respectively. The PNA modified vinblastine cationic liposomes were approximately 100 nm in size with a positive potential. In vitro results showed that the targeting liposomes could significantly enhance cellular uptake, selectively accumulate in LLT cells, and dramatically initiate apoptosis via activating pro-apoptotic proteins and apoptotic enzymes, thus leading to the strongest antitumor efficacy to LLT cells. In vivo results demonstrated that the targeting liposomes could display a prolonged circulation time in the blood, accumulate more drug in tumor location, and induce most of tumor cells apoptosis. As a result, a robust overall antitumor efficacy in tumor-bearing mice was observed subsequently. In conclusion, the chemotherapy using the PNA modified vinblastine cationic liposomes could provide a potential strategy for treating non-small cell lung cancer.
Keywords: Cationic liposomes; Vinblastine; Peanut agglutinin; Non-small cell lung cancer;
Investigation of 3D ordered macroporous carbon with different polymer coatings and their application as an oral vaccine carrier by Qinfu Zhao; Qiang Zhang; Yang Yue; Jiahao Huang; Donghua Di; Yikun Gao; Xinyi Shao; Siling Wang (234-241).
Display Omitted3-D ordered macroporous carbon with different polymer coatings were developed as new oral vaccine immunological systems. Poly dimethyl diallyl ammonium (PDDA), polyethyleneimine (PEI) and chitosan (CTS), three different polymers with electropositive or adsorption-promoting properties, were chosen as the coating materials to endow the vaccine delivery systems with different surface properties. The bovine serum albumin (BSA) was used as a model vaccine. The three different polymer coated systems exhibited similar release rate which minimized the influence of release rate. The measured value of immunoglobulin G (IgG) titers suggested that the sustained release rate of BSA from polymer coated systems exhibited no strengthened effect on the immune response but could delay the appearance of the peak of the IgG titers compared with uncoated system. The electrostatic attraction between the mucosal and positively charged carrier would be useful during the whole immune experiment. In addition, using the coating material with the ability of enhancing mucosal adsorption was important in the mid-late period of immune. The immunoglobulin A (IgA) titers induced by the polymer coated systems were significantly higher than that induced by the oral BSA solution or i.m. BSA with Freund’s complete adjuvant (FCA) which suggested the successful mucosal immune response of the three different coated systems. Overall, this work provides valuable information for the development of oral vaccine delivery system.
Keywords: 3-D ordered macroporous carbon; Chitosan; Polyethyleneimine; Oral immunity; Release rate; Electrostatic attraction;
Prodrug approach to improve absorption of prednisolone by Ye Sheng; Xiaoyan Yang; Dhananjay Pal; Ashim K. Mitra (242-249).
Display OmittedAmino acid and dipeptide prodrugs have been developed to examine their potential in enhancing aqueous solubility and permeability as well as to bypass P-glycoprotein (P-gp) mediated cellular efflux of prednisolone. Prodrugs have been synthesized and identified with LC/MS/MS and NMR. Prodrugs displayed significantly higher aqueous solubility relative to prednisolone. These compounds also exhibited higher stability under acidic conditions relative to basic medium. -Erythromycin uptake remained unaltered in the presence of valine–valine–prednisolone (VVP) indicating lower affinity toward P-gp. Moreover, VVP generated significantly higher transepithelial permeability across MDCK-MDR1 cells compared to prednisolone. Importantly, [3H]-GlySar uptake diminished significantly in the presence of VVP indicating high affinity toward peptide transporters. Moreover, prednisolone was regenerated from VVP due to enzymatic hydrolysis in SIRC cell homogenate. Results obtained from these studies clearly suggest that peptide transporter targeted prodrugs is a viable strategy to improve aqueous solubility and overcome P-gp mediated cellular efflux of prednisolone.
Keywords: Prodrugs; Prednisolone; Peptide transporters; Efflux; Homogenate;
Encapsulation of teniposide into albumin nanoparticles with greatly lowered toxicity and enhanced antitumor activity by Xinyi He; Nanxi Xiang; Jinjie Zhang; Jing Zhou; Yao Fu; Tao Gong; Zhirong Zhang (250-259).
Teniposide–phospholipid complex albumin nanoparticle (VM-E80-AN) was prepared by high pressure homogenization method which decreased myelosuppression in normal rats and enhanced therapeutic efficacy in B16 melanoma lung metastasis mice after i.v. injection.Display OmittedTeniposide (VM-26) is a semisynthetic derivative of podophyllotoxin effective for the treatment of many types of tumors. However, the poor water solubility and adverse effects restrict its clinical use. Our study aimed to develop a novel phospholipid complex albumin nanoparticle (VM-E80-AN) to reduce the systemic toxicity and enhance antitumor activity of VM-26. Egg yolk lecithin E80 and human serum albumin (HSA) were used as the main excipients to replace Cremophor EL in the commercial formulation. The physicochemical properties of VM-E80-AN were characterized to optimize the formulation. Cell and animal studies were further carried out to estimate its tumor inhibition efficacy, biodistribution, and toxicity. Comparison between VM-26 solution and VM-E80-AN showed that VM-E80-AN significantly reduced the toxicity of VM-26 and enhanced the anticancer efficacy of the drug. Thus, VM-E80-AN represents a safe and promising formulation of teniposide for clinical application.
Keywords: Teniposide; Phospholipid complex; Albumin; Nanoparticle; Antitumor; Toxicity;
Drug loading optimization and extended drug delivery of corticoids from pHEMA based soft contact lenses hydrogels via chemical and microstructural modifications by Eva García-Millán; Sandra Koprivnik; Francisco Javier Otero-Espinar (260-269).
Display OmittedThis paper proposes an approach to improve drug loading capacity and release properties of poly(2-hydroxyethyl methacrylate) (p(HEMA)) soft contact lenses based on the optimization of the hydrogel composition and microstructural modifications using water during the polymerization process.P(HEMA) based soft contact lenses were prepared by thermal or photopolymerization of 2-hydroxyethyl methacrylate (HEMA) solutions containing ethylene glycol di-methacrylate as crosslinker and different proportions of N-vinyl-2-pyrrolidone (NVP) or methacrylic acid (MA) as co-monomers. Transmittance, water uptake, swelling, microstructure, drug absorption isotherms and in vitro release were characterized using triamcinolone acetonide (TA) as model drug. Best drug loading ratios were obtained with lenses containing the highest amount (200 mM) of MA. Incorporation of 40% V/V of water during the polymerization increases the hydrogel porosity giving a better drug loading capacity.In vitro TA release kinetics shows that MA hydrogels released the drug significantly faster than NVP-hydrogels. Drug release was found to be diffusion controlled and kinetics was shown to be reproducible after consecutive drug loading/release processes. Results of p(HEMA) based soft contact lenses copolymerized with ethylene glycol dimethacrylate (EGDMA) and different co-monomers could be a good alternative to optimize the loading and ocular drug delivery of this corticosteroid drug.
Keywords: Ophthalmic drug delivery; Therapeutic soft contact lenses; Controlled drug release/delivery; Triamcinolone acetonide; Hydrogels; Poly(2-hydroxyethyl methacrylate); Microstructure;
Design and stability study of a paediatric oral solution of methotrexate 2 mg/ml by Sandy Vrignaud; Thomas Briot; Aurélie Launay; Marie Kempf; Frédéric Lagarce (270-273).
Display OmittedOral paediatric forms development by pharmaceutical industry is still insufficient. The present study was performed to propose an adapted and pleasant formulation of liquid oral formulation of MTX. The solution is composed of injectable methotrexate, water, Ora Sweet® and sodium bicarbonate.After 120 days storage, pH remained stable at about 8 in all formulations, insuring no risk of MTX precipitation. MTX content in solution formulation, determined by high performance liquid chromatography measurements, remained in the specifications of >90% of the initial concentration when stored at 4 and 25 °C. Forced degradation of MTX by heat and acidic conditions allowed formation and detection of degradation products by the analytical method.Microbial study of the preparation shows that the solution remains in the specifications during all the storage, or after one sample each week during one month, eventually indicating the microbial properties are not affected by patient use.To conclude, we here propose a new MTX liquid formulation stable for at least 120 days.
Keywords: Oral paediatric solution; Methotrexate; HPLC; Stability study;
Smart thermo/pH responsive magnetic nanogels for the simultaneous delivery of doxorubicin and methotrexate by Roya Salehi; Sepideh Rasouli; Hamed Hamishehkar (274-284).
Display OmittedTwo novel dual temperature/pH-sensitive superparamagnetic nanogels were developed with the aim of simultaneously delivering two different anticancer drugs, doxorubicin (DOX) and methotrexate (MTX). The studied copolymers were characterized by 1H NMR, SEM, and FTIR spectroscopy. Morphological investigations showed that both blank and drug-loaded nanogels had uniform shapes with a mean diameter of less than 30 nm. The drug storage/release behaviors were investigated. The nanogels showed an encapsulation efficiency of about 95% for both drugs. The cumulative in vitro release of the DOX/MTX-loaded nanogels exhibited an apparent thermo/pH-triggered controlled drug release in a sustained manner that was able to distinguish between tumor tissues. The cytotoxicity assay of a blank carrier to MCF7 and MDA-MB-231 cell lines indicated that the nanogels were suitable as drug carriers. Cell viability experiments further confirmed that the co-administration of DOX with MTX had a superior cytotoxicity to the mentioned cells compared with free dual drug- or single drug-loaded forms. Therefore, dual anticancer drug-loaded thermo/pH-sensitive nanogels have the potential to be used for cancer therapy, because they maintain a low premature drug release during blood circulation while having a rapid release upon reaching tumorous tissue.
Keywords: Cancer; Dual drug delivery; Magnetic nanogels; Stimuli-responsive; Targeted delivery;
Influence of pH and temperature on ziconotide stability in intrathecal analgesic admixtures in implantable pumps and syringes by Christophe Bazin; Anne-Lise Poirier; Denis Dupoiron (285-291).
Display OmittedThe aim of our study was to investigate the influence of pH and temperature on the stability of ziconotide in analgesic admixtures containing morphine and ropivacaine.All admixtures were combined using a wide range of concentrations, in implantable pumps and syringes, using temperatures from 4 °C to 37 °C. Quantification was made thanks to a specific chromatographic technique. pH has also been measured throughout the study.Admixtures confirm excellent stability for morphine and ropivacaine. Concerning ziconotide, an acid hydrolysis has been observed, reducing the time of use of our admixtures in a significant way, but producing non-toxic degradation products. The degradation was linear in all conditions. Inside the implantable pumps at body temperature turned out to be the best conditions for lower protein breakdown. Finally the degradation process showed a high correlation with the pH and the morphine concentration with a median loss of concentration delay due to degradation of 3.5 days [3; 5] when pH < 4.5 and 13 days [13; 24] when pH ≥ 4.5.Our admixtures showed different stability depending on the drug concentrations, pH and temperature. The great majority of mixtures in real life in our institution have stability highly compatible with our practice and with the delay between two pump refilling.
Keywords: Ziconotide; Morphine; Ropivacaine; Stability; Analgesia; Intrathecal;
Divalent toxoids loaded stable chitosan–glucomannan nanoassemblies for efficient systemic, mucosal and cellular immunostimulatory response following oral administration by Harshad Harde; Krupa Siddhapura; Ashish Kumar Agrawal; Sanyog Jain (292-304).
Display OmittedThe present study reports dual tetanus and diphtheria toxoids loaded stable chitosan–glucomannan nanoassemblies (sCh–GM-NAs) formulated using tandem ionic gelation technique for oral mucosal immunization. The stable, lyophilized sCh–GM-NAs exhibited ~152 nm particle size and ~85% EE of both the toxoids. The lyophilized sCh–GM-NAs displayed excellent stability in biomimetic media and preserved chemical, conformation and biological stability of encapsulated toxoids. The higher intracellular APCs uptake of sCh–GM-NAs was concentration and time dependent which may be attributed to the receptor mediated endocytosis via mannose and glucose receptor. The higher Caco-2 uptake of sCh–GM-NAs was further confirmed by ex vivo intestinal uptake studies. The in vivo evaluation revealed that sCh–GM-NAs posed significantly (p < 0.001) higher humoral, mucosal and cellular immune response than other counterparts by eliciting complete protective levels of anti-TT and anti-DT (~0.1 IU/mL) antibodies. Importantly, commercial ‘Dual antigen’ vaccine administered through oral or intramuscular route was unable to elicit all type of immune response. Conclusively, sCh–GM-NAs could be considered as promising vaccine adjuvant for oral mucosal immunization.
Keywords: Vaccine; Chitosan-glucomannan nanoassemblies; Glucomannosylation; Stability; Mucosal immunity;
Development of mucoadhesive microbeads using thiolated sodium alginate for intrapocket delivery of resveratrol by Abeer Ahmed Kassem; Ragwa Mohamed Farid; Doaa Ahmed Elsayed Issa; Doaa Said Khalil; Mona Yehia Abd-El-Razzak; Hussein Ibrahim Saudi; Heba Mohamed Eltokhey; Enas Arafa El-zamarany (305-313).
Display OmittedResveratrol (Res), a polyphenolic phytoalexin, had shown a promising therapeutic efficacy towards treatment of periodontal disease in vitro. This work aims to develop Res microbeads with strong mucoadhesion using thiolated alginate (TA) for local treatment of periodontal pockets. TA was synthesized by conjugating sodium alginate (A) with thioglycolic acid. Product was evaluated by IR and DSC. Both A and A:TA Res microbeads with different ratios were prepared by ionotropic gelation method. Formulations were evaluated regarding their entrapment efficiency (%EE), swelling index (SI), in vitro drug release and kinetics. Selected formula was examined for its mucoadhesion by ex vivo wash-off method, surface morphology using scanning electron microscope (SEM) and stability against light. Clinical evaluation is running.Formation of TA was confirmed. %EE for all formulations ranged from 83.72 to 104.54%. Results revealed a significant lower SI for TA rich formulation (A/TA 1:1) along with slower release rate and zero-order kinetics, in addition to powerful mucoadhesion; 26% remaining of microbeads after 1 h, compared to 2% for A microbeads. SEM micrographs showed a rough surface with drug precipitation. The formula maintained its %EE after 5 h exposure to direct sunlight. A/TA 1:1 mucoadhesive Res microbeads could be exploited as a prolonged drug release devices for intrapocket application.
Keywords: Polyphenol; Ionotropic gelation; Alginate – thioglycolic acid conjugate; Periodontal;
Development of gastro-resistant tablets for the protection and intestinal delivery of Lactobacillus fermentum CECT 5716 by María José Martín Villena; Ferderico Lara-Villoslada; María Adolfina Ruiz Martínez; María Encarnación Morales Hernández (314-319).
Display OmittedDifferent studies have attributed health benefits to Lactobacillus fermentum CECT 5716. However, the main problem associated with probiotics, is their low resistance to environmental and technological factors. Actually, probiotics are marketed as capsules or sachets, but few probiotic tablets exist. The aim of this study was to design tablets made out of functional polymers (formula 1: methocel K-15-sodium alginate; formula 2: Eudragit® L-100–sodium alginate; formula 3: cellulose acetate phthalate) that improve the stability and survival of probiotics. Rigid tablets were produced through direct compression with a bacterial content of 109 CFU/tablet (9 log CFU). Tablets were shown to improve the survival of cells when exposed to an acidic medium as compared to free cells. Eudragit® L-100–sodium alginate was found to be the most suitable excipient for the protection of probiotic within gastric conditions, resulting in the survival of 109 CFU (9 log CFU) after 2 h of incubation. Finally, these tablets were found to be stable over 6 months when stored at 4 °C. No significant differences were reported between the number of cells at time cero and after 6 months of storage at 4 °C (p > 0.05). In conclusion, direct compression using Eudragit® L-100–sodium alginate seems to be a suitable to produce probiotics tablets and could confer protection during passage trough stomach and storage.
Keywords: Probiotics; Tablets; Lactobacillus fermentum; Protection;