To compare the relative bioavailability and pharmacokinetic characteristics of a newly single pill combination of finasteride and tamsulosin with a conventional combination of finasteride and tamsulosin in healthy subjects with a single dose, randomized, open-label, 2-sequence -2period crossover study.

This single dose, open label, balanced, randomized, two-treatment, two-period, two-sequence, crossover study was conducted to compare the relative bioavailability and pharmacokinetic characteristics of a newly developed formulation with a conventional formulation in healthy subjects.

For this, a single-center, randomized, single-dose, open-label, 2-period and 2-sequence crossover study with a 14-day washout period was conducted in 26 healthy volunteers. Plasma samples for the analysis of finasteride/tamsulosin were collected up to 48 h after drug administration. Participants received either reference (in combination of of 0.2mg tamsulosin and 5mg finasteride) or test drug formulation (single pill combination of 0.2mg tamsulosin and 5mg finasteride) in the first period and the alternative formulation in the second period. Plasma concentrations of both tamsulosin and finasteride were determined by validated high-performance liquid chromatography coupled to tandem mass spectrometry detection. Pharmacokinetic parameters, including Cmax and AUC, were determined by noncompartmental analysis. Analysis of variance (ANOVA) was carried out using log-transformed Cmax and AUC, and the mean ratios and their 90% confidence intervals (CI) were calculated. According to regulatory requirements set forth by Korea and the US Food and Drug Administration, products meet the criteria for bioequivalence if the 90% CIs of the mean ratios for Cmax and AUC are within the range of 0.80 to 1.25.

Inclusion Criteria:

• Males age 20 to 45 years
• Body weight > 50 kg with 18~29 kg/m2 body mass index (BMI)
• Signed and dated informed consent form which meets all criteria of current FDA and KFDA regulations

Exclusion Criteria:

• subjects with acute conditions.
• presence of history affecting ADME
• Clinically significant history or current evidence of a hepatic, renal, gastrointestinal, or hematologic abnormality
• Hepatitis B, hepatitis C, or HIV infection revealed on the laboratory findings
• Any other acute or chronic disease
• A history of hypersensitivity to donepezil
• A history of alcohol or drug abuse
• Participation in another clinical trial within 3 months
• smoked >10 cigarettes daily
• consumption over 5 glasses daily of beverages containing xanthine derivatives
• use of any medication having the potential to affect the study results within 10 days before the start of the study.
• AST or ALT > 1.25 of upper normal limit
• total bilirubin > 1.5 of upper normal limit
• systolic blood pressure < 90 mmHg
• calculated CLcr using Cockroft-Gault equation < 50 mL/min