The purpose of this study is to compare the bioavailability (rate and extent of absorption) of two tansulosine 0,4 mg capsule formulations. An open, randomized, two-period crossover study with a seven-days washout interval was conduced in 32 healthy male volunteers. The plasma samples were obtained up to 72 hours after drug administration. A sensitive and specific LC-MS/MS method was developed and validated for the determination of tansulosine in human plasma. Bioequivalence between the products was determined by calculating 90% confidence intervals for the ratio of Cmax, AUC 0-72h and AUC 0--inf.

The study protocol was approved by Local Ethics Committee (UNICAMP - Campinas, Brazil). The study was performed with 32 healthy male volunteers. They were within 10% of their ideal body weight. Biochemical test and physical examination were carried out. Their medical history was also obtained. . Volunteers did not drink caffeine-containing drinks 48-hours before the study. The volunteers gave written informed consent to participate in study.

The study was designed as two-single-dose, randomized, open-label, balanced, crossover study, with two periods separated by 7-days washout. In both periods after a standard breakfast volunteers were given a single dose of their formulation (reference or test) of tansulosine with 200 mL of water. Blood samples (8 ml) were collected at 0 (pre-dose) and at 01:00; 02:00; 03:00; 04:00; 04;30; 05:00; 05:20; 05:40; 06:00; 06:20; 06:40; 07:00; 07:30; 08:00; 08:30; 09:00; 10:00; 12:00; 24:00; 48:00; 72:00h. These samples were centrifuged immediately and kept frozen at -20°C until the time of analysis. Standard meals were served at 4 and 8h after administration. During hospital confinement, volunteers were always under medical supervision.

Inclusion Criteria:

• They were within 10% of their ideal body weight.
• Biochemical test and physical examination were carried out.
• No concomitant medications were allowed.
• Volunteers did not drink caffeine-containing drinks 48-hours before the study.
• The volunteers gave written informed consent to participate in the study.

Exclusion Criteria:

• Chronic disease
• Smokers