目的 建立托拉塞米緩釋片的體外釋放度檢測方法并進行方法學研究，以所建立方法對自制與原研托拉塞米緩釋片體外釋放行為的一致性進行評價。方法 采用HPLC法分別測定托拉塞米自制片與原研制劑在水、0.1 mol/L鹽酸溶液、pH4.5醋酸鹽緩沖液、pH 6.8磷酸鹽緩沖液以及0.1 mol/L鹽酸溶液轉pH6.8磷酸鹽緩沖液中的累積釋放度，并用相似因子（f₂）法對釋放曲線的相似性進行評價。結果 當托拉塞米質量濃度在1.0~12.0 μg/mL時，其質量濃度與峰面積呈現良好的線性關系（r=0.999 5）；精密度試驗、溶液穩(wěn)定性試驗良好，供試液色譜峰峰面積的相對標準偏差均小于2.0%；準確度試驗平均回收率為100.04%，相對標準偏差為0.54%（n=12）；自制片的批內均一性符合技術要求，6個溶出杯內各取樣點的相對標準偏差均<10%；托拉塞米緩釋自制片與原研制劑在5種不同的釋放介質中f₂因子分別為72、60、77、66、60。結論 本文所建立方法可用于托拉塞米緩釋片釋放度的檢測，托拉塞米緩釋片自制產品與原研產品體外釋放行為一致。

Objective To establish a method for determining the dissolution of torasemide sustained-release tablet in vitro and study the methodology of the determination. The consistency of the in vitro release behavior between self-prepared torasemide sustained-release tablet and original preparation were evaluated by constructed method.Methods HPLC method was applied to detect the cumulative release percentage of self-prepared torasemide sustained-release tablet and original preparation in five kinds of release media (water, 0.1 mol/L hydrochloric acid solution, pH 4.5 acetate buffer, pH 6.8 phosphate buffer, and 0.1 mol/L hydrochloric acid solution turn to pH 6.8 phosphate buffer). Similarity factor (f₂) was used to evaluate the similarity of release curves.Results There was a good linear relationship between the quality concentration of torasemide and peak area in the range of 1.0-12.0 μg/mL (r=0.999 5).Results of precision and stability tests were good, and the RSDs for probational liquid were all lower than 2.0%. The average recovery of accuracy test was 100.04%, and RSD was 0.54% (n=12). The homogeneity of within group of self-prepared preparation met the technical requirement, RSDs of each sampling points in six Dissolution Vessels were lower than 10.0%. The f₂ factors of self-prepared torasemide sustained-release tablet and original preparation were 72, 60, 77, 66, and 60 in five kinds of release media.Conclusion The method in the paper is suitable for the release test of torasemide, meanwhile, the self-prepared tablet shows consistent in vitro release behavior with that of the original preparation.