Jagtap Y M, Bhujbal R K, Ranade A N, Ranpise N S
Department of Pharmaceutics, STES's Sinhgad College of Pharmacy, Vadgaon (Bk.), Pune-411 041, India.
Indian J Pharm Sci. 2012 Nov;74(6):512-20. doi: 10.4103/0250-474X.110578.
Floating microspheres have emerged as a potential candidate for gastroretentive drug delivery system. For developing a desired intragastric floatation system employing these microspheres, it is necessary to select an appropriate balance between buoyancy and drug releasing rate. These properties mainly depend on the polymers used in the formulation of the microspheres. Hence it is necessory to study the effect of these polymer concentrations on the various physicochemical properties of the microspheres. Floating microspheres were prepared by emulsion solvent evaporation technique utilising different polymers such as ethyl cellulose, Eudragit(®) RS and Eudragit(®) RL by dissolving them in a mixture of dichloromethane and methanol. Release modifiers studied were hydroxypropyl methylcellulose K4M, hydroxypropyl methylcellulose E50 LV and Eudragit(®) EPO. Prepared microspheres were analysed for particle size, surface morphology, entrapment efficiency, buoyancy, differential scanning calorimetry and in-vitro drug release. Ethyl cellulose and Eudragit(®) EPO resulted microspheres with high percentage yield, excellent spherical shape but had very less buoyancies with a high cumulative drug release. Ethyl cellulose microspheres prepared using hydroxypropyl methylcellulose K4M showed more sustained drug release and high buoyancies than that of the microspheres formulated with the hydroxypropyl methylcellulose E50 LV. Amongst these hydroxypropyl methylcellulose E50 LV showed good balance between buoyancy and the drug release.
漂浮微球已成为胃滞留药物递送系统的一个潜在候选者。为了利用这些微球开发出理想的胃内漂浮系统，有必要在浮力和药物释放速率之间选择一个合适的平衡点。这些特性主要取决于微球制剂中使用的聚合物。因此，有必要研究这些聚合物浓度对微球各种物理化学性质的影响。通过乳液溶剂蒸发技术，将不同的聚合物如乙基纤维素、Eudragit® RS和Eudragit® RL溶解在二氯甲烷和甲醇的混合物中，制备了漂浮微球。所研究的释放调节剂有羟丙基甲基纤维素K4M、羟丙基甲基纤维素E50 LV和Eudragit® EPO。对制备的微球进行了粒径、表面形态、包封率、浮力、差示扫描量热法和体外药物释放分析。乙基纤维素和Eudragit® EPO制备的微球产率高、球形良好，但浮力很小且药物累积释放率高。使用羟丙基甲基纤维素K4M制备的乙基纤维素微球比用羟丙基甲基纤维素E50 LV制备的微球表现出更持久的药物释放和更高的浮力。在这些微球中，羟丙基甲基纤维素E50 LV在浮力和药物释放之间表现出良好的平衡。
