甲硝唑生物粘附微球的体外释药及其粘附性

目的研制具有良好粘附性能和缓释效果的甲硝唑生物粘附微球(Metro-EC-CP微球)。方法通过液中干燥法制备Metro-EC-CP微球。对微球理化性质、体外释药及在SD大鼠体内胃粘膜上的粘附性进行了研究。结果 微球的平均粒径为559.87 μm。体外释药符合一级动力学。微球的释药速率随着粒径的增加及载药量的减少而减慢。Metro-EC-CP微球中粘附性材料CP含量增加,其生物粘附性能增加,而其缓释效果降低。结论乙基纤维素(EC)-卡波姆934P(CP)为17∶3、载药量为25%的微球在动物体内具有良好的胃粘膜粘附性能,药物缓释达8 h。     

盐酸小檗碱鼻用凝胶的研究

[目的]小檗碱具有神经保护作用,特别对神经退行性疾病具有良好的治疗效果,鼻腔给药为一种向脑输送药物的新途径,药物滴人鼻腔后能传人脑脊液达到治疗神经的目的,设计一种盐酸小檗碱鼻用凝胶剂,并对其进行体外扩散评价。[方法]以卡伯姆-980为凝胶基质,以丙三醇为潜溶剂,用三乙醇胺调节pH和黏度,采用正交设计对处方进行优化,用紫外分光光度法测定体外溶出,并溶出数据进行Weibull概率拟合。[结果]盐酸小檗碱鼻用凝胶最佳处方为卡波姆-980浓度0.2%,载药量1%,pH在6.0~7.0范围内,平均黏度约为1 000~1 200 mPa·s,体外溶出结果经Weibull概率模型拟合,其Td值为104.8 min。[结论]以生物黏附性材料卡波姆-980为基质制备盐酸小檗碱鼻用凝胶,处方简单,质量稳定,药物释放平稳。     

氟康唑粘附凝胶的研制

目的 :开发氟康唑粘附凝胶。方法 :以氟康唑为主药 ,卡波姆、甘油及其它溶剂为辅料 ,制备氟康唑粘附凝胶 ,并进行药剂学、质量标准方法学研究。结果与结论 :本方法制备工艺简单 ,性质稳定 ,所得氟康唑粘附凝胶有望成为理想的外用抗真菌制剂     

Pharmacological evaluation of membrane-moderated transdermal system of glipizide

1. Membrane-moderated transdermal systems of glipizide were prepared using drug-containing carbopol gel (drug reservoir) and ethyl cellulose, as well as Eudragit RS-100, Eudragit RL-100 (Rohm Pharma, Darmstadt, Germany) and ethylene vinyl acetate (EVA; 2, 9 and 19% vinyl acetate content) rate-controlling membranes, and were subsequently evaluated in vitro (drug content and drug permeation studies) and in vivo (acute and long-term hypoglycaemic activity, effect on glucose tolerance, biochemical and histopathological studies, skin irritation test and pharmacokinetic studies in mice). 2. The drug content of the systems was found to be more than 99%. Variations in drug permeation patterns were observed among the formulations containing different rate-controlling membranes. 3. The system with the EVA (19% vinyl acetate) rate-controlling membrane was selected for in vivo experiments. This transdermal system produced better improvement with respect to hypoglycaemic activity, glucose tolerance and tested biochemical, histopathological and pharmacokinetic parameters all compared with oral administration and exhibited negligible skin irritation. 4. The transdermal system successfully prevented severe hypoglycaemia in the initial hours and it was also effective for chronic application.     

Novel carbopol-based transfersomal gel of 5-fluorouracil for skin cancer treatment: in vitro characterization and in vivo study

Abstract

5-fluorouracil (5-Fu) is an antineoplastic drug, topically used for the treatment of actinic keratosis and nonmelanoma skin cancer. It shows poor percutaneous permeation through the conventionally applicable creams and thus inefficient for the treatment of deep-seated skin cancer. In the present article, transfersomal gel containing 5-Fu was investigated for the treatment of skin cancer. Different formulation of tranfersomes was prepared using Tween-80 and Span-80 as edge activators. The vesicles were characterized for particle size, shape, entrapment efficiency, deformability and in vitro skin permeation. Optimized formulation was incorporated into 1% carbopol 940 gel and evaluated for efficacy in the treatment of skin cancer. 5-Fu-loaded transfersomes (TT-2) has the size of 266.9?±?2.04?nm with 69.2?±?0.98% entrapment efficiency and highest deformability index of 27.8?±?1.08. Formulation TT-2 showed maximum skin deposition (81.3%) and comparable transdermal flux of 21.46?µg/cm²?h. The TT-2-loaded gel showed better skin penetration and skin deposition of the drug than the marketed formulation. Composition of the transfersomal gel has been proved nonirritant to the skin. We concluded that the developed 5-Fu-loaded transfersomal gel improves the skin absorption of 5-Fu and provide a better treatment for skin cancer.     

Evaluation of Carbopol-Methyl Cellulose Based Sustained-Release Ocular Delivery System for Pefloxacin Mesylate Using Rabbit Eye Model

The major purpose of this study was to develop and characterize a series of carbopol- and methyl cellulose–based solutions as the in situ gelling vehicles for ophthalmic drug delivery. The rheological properties, in vitro release as well as in vivo pharmacological response of a combination of polymer solutions, including carbopol and methyl cellulose, were evaluated. It was found that the optimum concentration of carbopol solution for the in situ gel-forming delivery systems was 0.3% (w/w), and that for methyl cellulose solution was 1.5% (w/w). The mixture of 0.3% carbopol and 1.5% methyl cellulose solutions showed a significant enhancement in gel strength in the physiological condition; this gel mixture was also found to be free flowing at pH 4.0 and 25°C. The rheological behaviors of carbopol/methyl cellulose solution were not affected by the incorporation of the drug. Drug levels in the aqueous humor of the rabbits were well above the MIC-values of relevant bacteria after 12 hours, the results of an optimized formulation containing 0.18% of pefloxacin mesylate compared well with the 0.3% marketed eye drop formulation, indicating our formulation to be significantly better considering that a similar effect was obtained at half the concentration. Both the in vitro release and in vivo pharmacological studies indicated that the carbopol/methyl cellulose solution had better ability to retain drug than did the carbopol or methyl cellulose solutions alone. The results demonstrated that the carbopol/methyl cellulose mixture can be used as an in situ gelling vehicle to enhance the ocular bioavailability of pefloxacin mesylate.     

潘生丁凝胶剂的研制及质量控制

应用新药用辅料高粘度的卡伯波－９４０（ｃａｒｂｏｐｏｌ－９４０）研制外用的潘生丁凝胶剂。用紫外分光光度分析方法测定双嘧达莫含量，其方法稳定、简单易行。卡伯波－９４０配制的凝胶，外观细腻美观，涂擦皮肤滑润舒适，易洗涤，对皮肤藕合性能良好，经初步用于治疗单纯疱疹和带状疱疹有较满意的疗效。     

羟丙基甲基纤维素-卡波普缓释亲水凝胶骨架片的研制和释药影响因素的考察

 目的 以盐酸苯丙醇胺（PPA）为模型药物,以羟丙基甲基纤维素(HPMC) K100M和卡波普971P为骨架材料,研制具有良好缓释特性的亲水凝胶骨架片,并考查影响释药的因素。方法 粉末直接压片法制备骨架片,反相高效液相色谱法检测释放介质中PPA的浓度。运用正交设计法,以美国的PPA缓释片Acutrim^?为对照,相似因子f₂值为指标,筛选较优处方,并考察影响PPA释放的因素。结果 释药曲线均符合Higuchi方程（R＞0.98,P＜0.01）。正交设计获得的最优处方在0.1 mol·L^-1HCl,H₂O（pH6.5）,磷酸盐缓冲液（PBS）pH 5.0,6.8和7.4的介质中,以及在0.1 mol·L^-1HCl中释放2 h,转移至pH 6.8 PBS中释放10 h,相对于对照品的f₂值为63～74,表明在各介质中两制剂的释药曲线相似。在本实验考察范围内,骨架片在水中的释药速率与HPMC K100M和卡波普971P的用量呈负相关。HPMC K100M和卡波普971P的比例（保持聚合物总用量相同）,硬脂酸镁用量和骨架片硬度对释药速率无显著性影响。结论 以HPMC K100M和卡波普971P为骨架材料的PPA亲水凝胶骨架片具有明显的缓释效果,影响药物释放的主要因素是HPMC K100M和卡波普 971P的用量。     

Modelling Mucoadhesion by Use of Surface Energy Terms Obtained from the Lewis Acid–Lewis Base Approach. II. Studies on Anionic,Cationic, and Unionisable Polymers

Surface energies of carbopol, chitosan, hydroxypropyl cellulose (HPC) and poly(HEMA) were assessed from contact angle and surface tension experiments. The surface energy was considered in terms of an apolar Lifshitz-van der Waals term and a polar acid-base term, which in turn is divided into electron donor and electron receptor (Lewis acid-Lewis base) contributions. Using these surface energy terms the interaction of dry and hydrated polymer with mucin in the presence of either artificial gastric or intestinal fluid, or saline was predicted. The predictions were related to measured forces of detachment. There was a significant difference between the surface energy on dry and hydrated HPC and also for carbopol; for the other polymers either the surface energy of the hydrated material was not detectable, or the effect of hydration was minimal. There were good correlations between mucoadhesive strength and the calculated free energies of interaction between mucin and polymer in the presence of each of the fluids, for each individual polymer. Thus, two trends were observed, one for unionisable and the other for ionisable polymers. It is argued that the increased mucoadhesion seen with ionisable polymers (compared with the predicted value based on results of unionisable polymers) is a direct result of the ionic interaction. No attempt has been made to correct for the ionisation effect, but the surface energy predictions provide insight into the mechanism of the mucoadhesion process. This approach is useful for understanding and predicting interactions between different materials and biological components.     

In Vitro and in Vivo Evaluation of Mucoadhesive Microspheres Prepared for the Gastrointestinal Tract Using Polyglycerol Esters of Fatty Acids and a Poly(acrylic acid) Derivative

Two types of polyglycerol ester of fatty acid (PGEF)-based microspheres were prepared: Carbopol 934P (CP)-coated microspheres (CPC-microspheres) and CP-dispersion microspheres (CPD-microspheres). Comparative studies on mucoadhesion were done with these microspheres and PGEF-based microspheres without CP (PGEF-microspheres). In an in vitro adhesion test, the CPD-microspheres adhered strongly to mucosa prepared from rat stomach and small intestine because each CP particle in the CPD-microsphere was hydrated and swelled with part of it remaining within the microsphere and part extending to the surface serving to anchor the microsphere to the mucus layer. The gastrointestinal transit patterns after administration of the CPD-microspheres and PGEF-microspheres to fasted rats were fitted to a model in which the microspheres are emptied from the stomach monoexponentially with a lag time and then transit through the small intestine at zero-order. Parameters obtained by curve fitting confirmed that the gastrointestinal transit time of the CPD-microspheres was prolonged compared with that of the PGEF-microspheres. MRT in the gastrointestinal tract was also prolonged after administration of the CPD-microspheres compared with that following the administration of the PGEF-microspheres.