RESUMEN
OBJECTIVE：To investigate the in vitro quality consistency of domestic Nitroglycerin table t imitative preparation and reference preparation （original drug ）. METHODS ：The contents of nitroglycerin and related substances in 1 batch of Nitroglycerin tablet reference preparation （manufacturer A ）and 4 batches of imitative preparation （manufacturer B ，C，D，E） were determined according to Nitroglycerin Tablet Import Drugs Registration Standard JX 20010267. The paddle method of dissolution determination method was adopted ，with the rotating speed of 50 r/min. HPLC method was adopted to determine the dissolution amount of 5 batches of above preparations in 4 kinds of dissolution mediums （pH 1.2 hydrochloric acid solution ，pH 4.0 acetate buffer solution ，pH 6.8 phosphate buffer solution ，water） within 10 min.The accumulative dissolution rate was calculated，and dissolution curves of samples were drawn.The similarity of the dissolution curves was evaluated by calculating similarity factor （f2）of 2，5，8 min accumulative dissolution rate. RESULTS ：The contents of nitroglycerin in the preparations from manufacturer A ，B，C，D，E were 99.8％，98.3％，94.0％，93.3％，96.7％，respectively（n＝2）；the contents of related substance were 0.46％，0.55％，0.63％，0.72％，0.49％，respectively（n＝2）. Using reference preparation of manufacturer A as control，f2 of imitative preparation from manufacturer B ，C，D，E were 74，28，25，67 in pH 1.2 hydrochloric acid solution ；76， 26，28，84 in pH 4.0 acetate buffer solution ；79，39，35，71 in pH 6.8 phosphate buffer solution ；69，32，37，62 in water ， respectively. CONCLUSIONS ：The method is suitable for in vitro quality consistency evaluation of Nitroglycerin table timitative preparation. Compared with reference preparation ，the contents of main components in the imitative preparations from manufacturer C，D are lower ；in vitro dissolution curves of those imitative preparation are not similar to reference preparation .