目的 制備美托拉宗緩釋片并探討其釋藥機制。方法 從處方和工藝兩個方面考察了各因素對藥物釋放行為的影響。在單因素考察的基礎(chǔ)上，采用羥丙甲基纖維素（HPMC） 4000 cps作為骨架材料 HPMC 5 cps作為致孔劑，制備美托拉宗緩釋片。通過正交設(shè)計，以2、4、7 h的藥物釋放度為評價指標(biāo)，優(yōu)化最佳處方。結(jié)果 HPMC的用量和比例對美托拉宗緩釋片的釋放影響最大。該制劑的體外釋放與Ritger-Peppas方程擬合的相關(guān)性最好，釋藥過程為擴散和溶蝕并存。結(jié)論 美托拉宗緩釋片的工藝重現(xiàn)性好，體外釋放符合擬定的釋藥速率。

Objective To prepare Metlazone Sustained Release Tablets, and study their release mechanisms. Methods The effects of many factors, including formulation and technique on the release behavior of Metlazone Sustained Release Tablets were investigated. Based on the comprehensive single-factor tests, Metlazone Sustained Release Tablets were prepared with HPMC 4000 cps as matrix material, and HPMC 5 cps as porogen. The formulations were optimized by orthogonal design with the accumulative release amounts of 2, 4, and 7 h has the evaluation target. Results The amounts and proportions of HPMC were major factors on release of Metlazone Sustained Release Tablets . The release behaviors of tablets followed Ritger-Peppas kinetics, and the drug was released by diffusion and corrosion mechanism. Conclusion The preparations of Metlazone Sustained Release Tablets has good repeatability and the release in vitro could meet the requirements.