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Huang D.,Sun Yat Sen University | Wang L.,Sun Yat Sen University | Dong Y.,Sun Yat Sen University | Pan X.,Sun Yat Sen University | And 3 more authors.
European Journal of Pharmaceutics and Biopharmaceutics

This study was designed to investigate the feasibility of silk fibroin nanoparticles (SFNs) for sustained drug delivery in transscleral ultrasound. Fluorescein isothiocynate labeled bovine serum albumin (FITC-BSA, MW 66.45 kDa) was chosen as a model macromolecular protein drug and SFNs were used as nano-carrier systems suitable for ocular drug delivery. Drug loaded nanoparticles (FITC-BSA-SFNs) were first prepared and characterized. In vitro transscleral study under ultrasound exposure (1 MHz, 0.5 W/cm2, 5 min continuous wave) using isolated sclera of rabbit was performed. The posterior eye segment of rabbit was examined for adverse effect by slit-lamp and histology. It was found that FITC-BSA-SFNs possessed sustained release, bioadhesive, and co-permeation characteristics. The ultrasound application significantly improved the penetration efficiency of FITC-BSA-SFNs as compared with passive delivery, meanwhile caused no damages to the ocular tissue and particles themselves. The distribution profile of SFNs revealed rapid and lasting adhesion on the outer scleral tissues, followed by migration into the interior up to one week after treatment. This research suggested a novel non-invasive transscleral administration of macromolecular protein drugs using SFN carriers combining with ultrasound technology. © 2014 Elsevier B.V. All rights reserved. Source

Peng T.,Sun Yat Sen University | Zhu C.,Sun Yat Sen University | Huang Y.,Sun Yat Sen University | Quan G.,Sun Yat Sen University | And 6 more authors.
Powder Technology

Objective: Granulated pellet-containing tablets (GPCT) prepared by a novel granulation technique showed better uniformity and compressibility over traditional pellet-containing tablets (PCT). The superiority of GPCT was mainly due to the excipient layer, which was laid over the coated pellets and modified the surface of pellets with increased roughness. Microcrystalline cellulose (MCC) was the main layering component which greatly influenced the stability of GPCT in storage, so was the additional excipients. The purpose of this study was to investigate the influence of excipient layer on the stability of GPCT. Methods: GP were prepared by layering the combination of various excipients with MCC over the coated pellets, and further compressed into GPCT. The drug release profiles from the coated pellets, GP, and GPCT were compared, and the drug degradation rate in GP and GPCT were evaluated under high temperature, strong light, and high humidity conditions for up to 10. days. Results: The drug content in GP and GPCT was above 97% after storage under high temperature and strong light, but dropped to 93%-96% under high humidity. The drug degradation rate in GP followed the order of excipient hygroscopicity as PVPP. > CMC-Na. >. Lactose, while GPCT with PVPP showed the least drug degradation, suggesting the stability of GPCT was mainly determined by the excipient compressibility. Conclusions: All formulations under high temperature and strong light were stable, indicating the influence of temperature and light could be ignored. Under high humidity conditions, the drug degradation in GP was in accordance with the excipient hygroscopicity, while it was dominated by excipient compressibility in GPCT. Therefore, the binary mixture of MCC and PVPP with the best compressibility may be ideal layering excipients to prepare acceptable GPCT for humidity sensitive drugs. © 2014 Published by Elsevier B.V. Source

Qin L.,Sun Yat Sen University | Qin L.,Guangdong Research Center for Drug Delivery Systems | Mei L.,Sun Yat Sen University | Shan Z.,Sun Yat Sen University | And 6 more authors.
Drug Development and Industrial Pharmacy

Phytantriol has received increasing amount of attention in drug delivery system, however, the ability of the phytantriol based liquid crystal as a novel embolic agent to provide a sustained release delivery system is yet to be comprehensively demonstrated. The purpose of this study was to prepare a phytantriol-based cubic phase precursor solution loaded with anticancer drug hydroxycamptothecine (HCPT) and evaluate its embolization properties, in vitro drug release and cytotoxicity. Phase behavior of the phytantriol-solvent-water system was investigated by visual inspection and polarized light microscopy, and no phase transition was observed in the presence of HCPT within the studied dose range. Water uptake by the phytantriol matrices was determined gravimetrically, suggesting that the swelling complied with the second order kinetics. In vitro evaluation of embolic efficacy indicated that the isotropic solution displayed a satisfactory embolization effect. In vitro drug release results showed a sustained-release up to 30 days and the release behavior was affected by the initial composition and drug loading. Moreover, the in vitro cytotoxicity and anticancer activity were evaluated by MTT assay. No appreciable mortality was observed for NIH 3T3 cells after 48 h exposure to blank formulations, and the anticancer activity of HCPT-loaded formulations to HepG2 and SMMC7721 cells was strongly dependent on the drug loading and treatment time. Taken together, these results indicate that phytantriol-based cubic phase embolic gelling solution is a promising potential carrier for HCPT delivery to achieve a sustained drug release by vascular embolization, and this technology may be potential for clinical applications. © 2015 Taylor & Francis. Source

Qin L.-Z.,Sun Yat Sen University | Qin L.-Z.,Guangdong Research Center for Drug Delivery Systems | Zhang X.,Sun Yat Sen University | Wu L.-N.,Sun Yat Sen University | And 5 more authors.
Yaoxue Xuebao

The purpose of this study is to investigate the preparation of hydroxycamptothecine (HCPT)-loaded cubic crystal liquid embolic precursor solution, and evaluate its in vitro embolic efficiency. Phytantriol was used as cubic crystal liquid embolic material, and the optimal formulation was selected according to ternary phase diagram. Polarized light microscopy, differential scanning calorimetry, and small angle X-ray scattering (SAXS) were used to characterize the cubic crystal structure. High performance liquid chromatography and X-ray diffraction analysis were used to investigate the lactone ring of HCPT. In vitro dissolution was preliminary evaluated, and the simulation embolic model was constructed to evaluate the embolic efficiency of precursor solution. Meanwhile, the gelation time and adhesion force were investigated. The results showed that HCPT-loaded precursor solution for embolization had been successfully prepared with low viscosity which was injectable. The precursor solution could transform into Pn3m structure liquid crystal phase gel rapidly when contracting with excess water. The formed HPCT gel remained its lactone form as the same in precursor solution, and expressed the good ability to block the saline flow, and HCPT could keep sustained releasing drug over 30 days. The prepared drug-loaded embolic precursor solution showed a promising potential for vascular embolization and application in clinical treatment of tumor. Source

Dong Y.,Sun Yat Sen University | Dong P.,Sun Yat Sen University | Huang D.,Sun Yat Sen University | Mei L.,Sun Yat Sen University | And 7 more authors.
European Journal of Pharmaceutics and Biopharmaceutics

The unique structure and protective mechanisms of the eye result in low bioavailability of ocular drugs. Using a mucoadhesive material is an efficient solution to improve ocular drug therapeutic efficacy. This study was designed to prepare a liposomal formulation coated by a novel adhesive excipient, silk fibroin (SF), for topical ocular drug delivery. The regenerated silk fibroins (SFs) with different dissolving time were coated onto the ibuprofen-loaded liposomes. The morphology, drug encapsulation efficiency, in vitro release and in vitro corneal permeation of SF-coated liposomes (SLs) were investigated in comparison with the conventional liposome. Cellular adhesion and cytotoxicity assay of SF and SLs were tested using human corneal epithelial cells (HCEC). SLs showed sustained drug release and in vitro corneal permeation of ibuprofen as compared to drug solution and conventional liposome. The cellular fluorescence appeared after 7 min of exposure to SF, and the intensity increased sustainedly up to 12 h with no detectable cytotoxicity. Higher fluorescence intensity of Nile red in SLs was observed in a short period of 15 min showing a rapid uptake. These favorable properties make SF-coated liposome be a promising ocular drug delivery system. © 2015 Elsevier B.V. All rights reserved. Source

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