Khan G M, Zhu J B
Department of Pharmaceutics, Faculty of Pharmacy, Gomal University, Dera Ismail Khan, N.W.F.P., Pakistan.
J Control Release. 1999 Feb 1;57(2):197-203. doi: 10.1016/s0168-3659(98)00122-9.
Controlled-release (CR) matrix tablets of ibuprofen (IBF) and Carbopol(R) 934P, and blended mixture of Carbopol(R) 934P and 971P resins, at different drug to polymers ratios, were prepared by the direct compression method. The investigation focuses on the influence of the proportion of the matrix material, and several co-excipients (lactose, microcrystalline cellulose (MCC), and starch) on the mechanism and release rate of the drug from the tablets. In vitro drug release in pH 7.2 phosphate buffer solution appears to occur both by diffusion and a swelling-controlled mechanism, exhibiting either anomalous or Case II type transport. The release process could be described by plotting the fraction released versus time and fitting data to the simple exponential model: Mt/Minfinity=ktn. The release kinetics were modified when the blended mixtures of Carbopol(R) 934P and 971P resins were used as the matrix materials. In general, all of the co-excipients, used in this study, enhanced the release rate of IBF. However, lactose demonstrated slower and more linear release behavior as compared to microcrystalline cellulose or starch. The dissolution T50 and T90 values for the three co-excipients were in the order of lactose>microcrystalline cellulose>starch.
采用直接压片法制备了不同药物与聚合物比例的布洛芬（IBF）与卡波姆934P的控释（CR）骨架片，以及卡波姆934P和971P树脂的混合混合物。研究重点在于骨架材料比例以及几种辅料（乳糖、微晶纤维素（MCC）和淀粉）对片剂中药物释放机制和释放速率的影响。在pH 7.2磷酸盐缓冲溶液中的体外药物释放似乎通过扩散和溶胀控制机制发生，呈现出非菲克或第二类转运。释放过程可以通过绘制释放分数与时间的关系图并将数据拟合到简单指数模型来描述：Mt/Minfinity=ktn。当使用卡波姆934P和971P树脂的混合混合物作为骨架材料时，释放动力学发生了改变。总体而言，本研究中使用的所有辅料均提高了IBF的释放速率。然而，与微晶纤维素或淀粉相比，乳糖表现出较慢且更呈线性的释放行为。三种辅料的溶出T50和T90值顺序为乳糖>微晶纤维素>淀粉。
