Bhoyar P K, Morani D O, Biyani D M, Umekar M J, Mahure J G, Amgaonkar Y M
S.K.B. College of Pharmacy, New Kamptee, Nagpur, Maharashtra, India.
J Young Pharm. 2011 Apr;3(2):105-11. doi: 10.4103/0975-1483.80293.
The objective of this study was to microencapsulate the anti-inflammatory drug (naproxen) to provide controlled release and minimizing or eliminating local side effect by avoiding the drug release in the upper gastrointestinal track. Naproxen was microencapsulated with lipid-like carnauba wax, hydrogenated castor oil using modified melt dispersion (modified congealable disperse phase encapsulation) technique. Effect of various formulation and process variables such as drug-lipid ratio, concentration of modifier, concentration of dispersant, stirring speed, stirring time, temperature of external phase, on evaluatory parameters such as size, entrapment efficiency, and in vitro release of naproxen were studied. The microspheres were characterized for particle size, scanning electron microscopy (SEM), FT-IR spectroscopy, drug entrapment efficiency, in vitro release studies, for in vitro release kinetics. The shape of microspheres was found to be spherical by SEM. The drug entrapment efficiency of various batches of microspheres was found to be ranging from 60 to 90 %w/w. In vitro drug release studies were carried out up to 24 h in pH 7.4 phosphate buffer showing 50-65% drug release. In vitro drug release from all the batches showed better fitting with the Korsmeyer-Peppas model, indicating the possible mechanism of drug release to be by diffusion and erosion of the lipid matrix.
本研究的目的是将抗炎药物（萘普生）微囊化，以实现控释，并通过避免药物在上消化道释放来最小化或消除局部副作用。采用改良熔融分散法（改良可凝结分散相包封技术），用类脂巴西棕榈蜡、氢化蓖麻油对萘普生进行微囊化。研究了各种配方和工艺变量，如药物-脂质比、改性剂浓度、分散剂浓度、搅拌速度、搅拌时间、外相温度，对评价参数如粒径、包封率和萘普生体外释放的影响。对微球进行了粒径、扫描电子显微镜（SEM）、傅里叶变换红外光谱（FT-IR）、药物包封率、体外释放研究以及体外释放动力学表征。通过扫描电子显微镜观察发现微球形状为球形。不同批次微球的药物包封率在60%至90%w/w之间。在pH 7.4的磷酸盐缓冲液中进行了长达24小时的体外药物释放研究，结果显示药物释放率为50%-65%。所有批次微球的体外药物释放与Korsmeyer-Peppas模型拟合良好，表明药物释放的可能机制是脂质基质的扩散和侵蚀。
