Study on Bioequivalence of Sustained-Release Isosorbide-5-Mononitrate Tablets

Objective To study pharmacokinetics and bioequivalence of Sustained-Release Isosorbide-5-Mononitrate tablets in health volunteers. Methods According to a randomized 2 way cross-over design, a single oral Sustained-Release Isosorbide-5-Mononitrate tablets and capsules were given to 20 male volunteers and multiple-dose to 10 male volunteers. The plasma concentrations were determined. The pharmacokinetic and bioavailbility of tablet were compared with its reference capsule. Results The pharmacokinetics parameters of sustained-release Isosorbide-5-Mononitrate tablet and capsule were as follows: After a single oral dose(40 mg), C_(max) were (540.8±155.6)和(492.1±84.9)μg.L~(-1);T_(max) were (4.65±0.88) and (5.85±(1.23))h;AUC_(0-36) were (7198.6±1135.9) and (6565.2±1162.1) μg.h.L~(-1).F_(0-36h) and F_(0-∞)were (110.8±13.1) and (110.5±13.0)%,respectively. After multiple-dose(40 mg), C_(max) were (632.7±142.3) and (641.5±264.4) μg.L~(-1); T_(max) were (4.80±1.14)and (5.40±1.07)h; C_(min) were(84.7±24.9)and (80.0±25.3)μg.L~(-1); C_(av) were (303.7±59.3) and (267.1±43.1) μg.L-1; AUC~(ss) were (7288.1±1423.5) and (6410.4±1033.8) μg.L~(-1); DF were (181.8±27.1) and (206.8± 56.9)%.According to AUC~(ss), F was (114.4±20.6)% .Bioequivalence concerning AUC_(0-36)、AUC_(0-∞)、C_(max) and C_(av) was assessed by calculating 90%-confidence intervals and no significant differences were found. Conclusion The result shows that two formulations are of bioequivalence.