Objective: This study was conducted to assess the pharmacokinetic and safety profiles between a new oral formulation of terazosin hydrochloride capsule compared with the brand-name drug.
Materials and methods: A randomized, open-label, single-dose, 2-period crossover study under fasting or fed conditions was conducted in healthy Chinese subjects. 24 individuals were selected, respectively. Each subject was randomized at the beginning to receive a 2-mg capsule of the test or the reference terazosin during the first period and then received the alternate formulation during the second period following a 1-week washout period. Blood samples were collected at pre-dose and up to 60 hours after administration. Plasma terazosin was quantified by a validated LC-MS/MS method.
Results: 48 healthy subjects were enrolled, and 47 completed the study. Cmax, AUC0-t, and AUC0-∞ were similar and the 90% CIs for the geometric mean ratios of these parameters between the two groups were all bounded within the predefined bioequivalence criterion of 80 - 125% under both fasting and fed conditions. Throughout the study period, a total of 30 treatment-emergent adverse events (TEAEs) were reported under fasting condition. 35 TEAEs were observed under fed conditions. No serious adverse event was observed.
Conclusion: The test and reference formulations of terazosin were bioequivalent and well tolerated under both fasting and fed conditions.