Pharmacokinetic properties of isosorbide-5-mononitrate under fasting and fed conditions in healthy male subjects

Objective: This study was performed to compare the pharmacokinetic properties and relative bioavailability of two isosorbide-5-mononitrate (5-ISMN) sustained-release drugs in healthy Korean subjects under fasting and fed conditions. Methods: A total of 60 healthy volunteers (30 each in the fasting and fed arms of the study) were enrolled in the study and were randomized to treatment. After the administration of a single dose of one of the investigational products, blood samples were collected at specific time intervals from 0 to 36 hours. The plasma concentrations of 5-ISMN were measured by LC-MS/MS. The pharmacokinetic parameters were calculated, and the 90% confidence intervals (CIs) of the geometric mean ratio (test/reference) of the parameters were obtained by analysis of variance on logarithmically transformed data. Results: The corresponding 90% CIs of AUC_last and C_max for the test/reference geometric mean ratio were 90.75 - 98.44% and 92.28 - 98.33%, respectively, under fasting conditions. In the fed state study, the 90% CIs for the geometric mean ratio of test to reference drugs were 94.79 - 103.33% for AUC_last and 99.86 - 108.02% for C_max. Conclusion: The test product is equivalent to the reference product in subjects under fasting and fed conditions within the Korean regulatory bioequivalence criteria. Both formulations were safe and well tolerated, and there were no noteworthy differences in the safety profiles between the test and reference drugs.