羟丙基甲基纤维素的凝胶特性及其对曲尼司特缓释片释放行为的影响

目的：研究羟丙基甲基纤维素(HPMC)的凝胶特性及其对曲尼司特缓释片释放行为的影响。方法：采用称重法、图像法和体积测量法,研究HPMC辅料片和曲尼司特缓释片在不同pH环境中的水合度和溶胀度。结果：辅料片在SGF和SIF中的水合速率常数分别为0.897 h-1和0.681 h-1；溶胀速率常数分别为1.005 h^-1和0.713 h^-1。曲尼司特缓释片在SGF中，在0.5 h内迅速水合和溶胀，其后呈负增长；而在SIF中，重量和体积都缓慢增加,5 h后重量稍有下降,体积保持不变。结论：HPMC水凝胶的形成速度和形态与介质的pH有关，凝胶层的溶蚀速度控制药物的释放。

THE HYDRATING AND SWELLING ACTION OF HPMC AND ITS INFLUENCE ON TRANILAST RELEASE FROM THE MATRICES IN VITRO

AIM: To study the influence of hydration and gelation of hydroxypropyl methyl cellulose (HPMC) in different medium on drug release from HPMC matrices. METHODS: Tablet press method was used to obtain the tranilast sustained release (Tra SR) tablet matrices consisting of hydroxypropyl methylcellulose (HPMC K 4m ) and pure HPMC tablet. The weights and dimensions of the HPMC tablets and the Tra SR tablets were measured using gravimetric method and micrometer screw gauge prior to hydrating and swelling determination in simulated intestinal fluid (SIF, pH 7 3) and simulated gastric fluid (SGF, pH 1 3) at definite time, respectively. RESULTS: For HPMC tablets, the hydrating rate constants are 0 897 h -1 in SGF and 0 681 h -1 in SIF; the swelling rate constants are 1 005 h -1 in SGF and 0 713 h -1 in SIF. For the Tra SR tablets, in SGF its weight and dimension increased quickly in the first half hour and then decreased slowly; but in SIF it increased slowly with prolongation of the immersion within 5 hours and then its dimension remained constant. CONCLUSION: The extent and velocity of hydrating and swelling of matrix were affected by the pH of the dissolution medium and period of time. The erosion of gel layer is a rate control factor for tranilast release from HPMC matrix sustained release tablet.