Pharmacokinetics and Bioequivalence of Tamsulosin Hydrochloride Extended-Release Capsules in Healthy Chinese Volunteers: A Randomized, Open-Label, Crossover Study Under Fasting and Fed Conditions.

Tamsulosin hydrochloride is a long-acting, highly selective α1A receptor antagonist, primarily used to treat benign prostatic hyperplasia. It effectively alleviates lower urinary tract symptoms, including dysuria, nocturia, and urgency caused by prostate enlargement. This study aimed to evaluate the pharmacokinetics and bioequivalence of two tamsulosin extended-release capsules in Chinese volunteers under both fasting and fed conditions. A single-center, randomized, open-label, two-formulation, single-dose, two-period, two-way crossover design was used. A total of 64 healthy volunteers were enrolled, with 28 in the fasting group and 36 in the fed group. In the fasting group, each subject received a single dose of either the test or reference formulation in a randomized crossover design. In the fed group, volunteers consumed a high-fat meal 1 h before dosing. Blood samples were collected for up to 72 h post-dose, and plasma tamsulosin concentrations were measured using liquid chromatography-tandem mass spectrometry. The geometric mean ratios and 90% confidence intervals for key exposure metrics for both formulations under fasting and fed conditions were within the 0.8000-1.2500 bioequivalence range. Both formulations demonstrated bioequivalence under both conditions, and no severe adverse events were observed.