Abstract: AIM: To compare the bioequivalence of test formulation compound isosorbide-mononitrat sustained release tablets (T) and reference formulation isosorbidemononitrat sustained release tablets and aspirin enteric coated tablets(R), and to evaluate release characteristics and degree of fluctuation of test formulation.METHODS: A high performance liquid chromatography method was used to deter_mine the time-plasma isosorbide-mononitrat and salicylic acid concentrations after a single and multiple oral doses of test and reference formulations in 18 healthy volunteers respectively in an open randomized twoway crossover experimental test.The pharmacokinetic parameters as well as relative bioavailability were calculated with DAS practical pharmacokinetic programme, variance and two one-side t-test were analyzed.RESULTS: The t_1/2, C_max, t_max, AUC0-t for isosorbide-mononitrat after a single oral dose of test and reference were 8.3 ±0.6 and 8.2 ±0.6 h, 0.51 ±0.09 and 0.52 ±0.09 mg·L ^-1, 4.8 ±0.4 and 4.6 ±0.3 h, 4.9 ±0.6 and 5.2 ± 0.8 mg·h ^-1 ·L ^-1, respectively, and the bioavailability of test was (96.1 ±10.8) %, and for salicylic acid, they were 2.4 ±0.3 and 2.5 ±0.3 h, 3.4 ±0.5 and 3.0 ± 0.4 mg·L ^-1, 1.7 ±0.2 and 4.9 ±0.3 h, 13.4 ±2.5 and 13.0 ±2.5 mg·h ^-1·L ^-1, respectively, and the bioavailability of test was (103.6 ±9.6) %.After multiple oral doses of test and reference, the C_max, C_min, DF for isosorbide-mononitrat were 0.68 ±0.14 and 0.67 ± 0.13 mg·L ^-1, 0.17 ±0.03 and 0.17 ±0.04 mg·L ^-1, (136 ±36) % and (140 ±42) %, respectively.CONCLUSION: The compound isosorbide-mononitrat sustained release tablets and isosorbide-mononitrat sustained release tablets and aspirin enteric coated tablets are bioequivalent; the isosorbide-mononitrat of test formulation has sustained release characteristics.

Key words: isosorbide-mononitrate, aspirin, salicylic acid, bioequivalence, high performance liquid chromatography