Khan Ferdous, Ibn Razzak Shaikhul Millat, Khan Ziaur Rahman, Azad Mohammad Abul Kalam, Chowdhury Jakir Ahmed, Reza Selim
Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Dhaka, Dhaka-1000, Bangladesh.
Pak J Pharm Sci. 2009 Apr;22(2):155-61.
This investigation describes the preparation and in vitro evaluation of gastroretentive floating tablet of theophylline. Two hydrophilic cellulose derivatives, Methocel K100M and Methocel K15MCR were evaluated for their gel forming and release controlling properties. Sodium bicarbonate and citric acid were incorporated as gas generating agents. The effects of soluble components (sodium bicarbonate and citric acid), gel forming agents and amount variation of theophylline on drug release profile and floating properties were investigated. Tablets were prepared by direct compression technique. Formulations were evaluated for in vitro buoyancy and drug release study was evaluated for eight hours using USP XXII paddle-type dissolution apparatus using 0.1N HCl as dissolution medium. The release mechanisms were explored and explained with zero order, first order, Higuchi and Korsmeyer equations. The release rate, extent and mechanisms were found to be governed by polymer and floating agent content. The content of active ingredient was also a vital factor in controlling drug release pattern. It was found that polymer content and amount of floating agent significantly affected the mean dissolution time, percentage drug release after 8 hours, release rate constant and diffusion exponent.
本研究描述了茶碱胃内滞留漂浮片的制备及其体外评价。对两种亲水性纤维素衍生物，即羟丙甲纤维素K100M和羟丙甲纤维素K15MCR的凝胶形成和控释性能进行了评价。加入碳酸氢钠和柠檬酸作为产气剂。研究了可溶性成分（碳酸氢钠和柠檬酸）、凝胶形成剂以及茶碱用量变化对药物释放曲线和漂浮性能的影响。采用直接压片技术制备片剂。使用USP XXII桨式溶出装置，以0.1N盐酸作为溶出介质，对制剂进行体外漂浮性评价，并进行8小时的药物释放研究。用零级、一级、Higuchi和Korsmeyer方程探讨并解释了释放机制。发现释放速率、程度和机制受聚合物和漂浮剂含量的控制。活性成分的含量也是控制药物释放模式的一个关键因素。发现聚合物含量和漂浮剂用量显著影响平均溶出时间、8小时后药物释放百分比、释放速率常数和扩散指数。
