Comparative Bioavailability of Sildenafil 50-mg Film-Coated Tablets and 50-mg Orally Disintegrating Films in Healthy Mexican Subjects: Results From a Randomized, Open-Label, Crossover Study

Abstract

An orally disintegrating film formulation of sildenafil 50 mg (CL Pharm Co, Ltd) was used in this study and compared to the market-available product film coated tablets (Viagra^® , Pfizer, Mexico). The objective was to compare the pharmacokinetic properties of these products after a single-dose administration to 47 healthy male volunteers (aged 19-48 years) in a randomized, open-label, 2-way crossover study. Each subject received a single oral dose of 50 mg of sildenafil test or reference product administered under fasting conditions at each of the 2 study periods according to a crossover design. There was a 3-day washout period between drug administrations. Blood samples for pharmacokinetic analysis were collected predose and at different times postdosing. The maximum plasma concentration and area under the curve from administration to last observed concentration time of test and reference products were compared. Pharmacokinetic parameters shown to be within the confidence interval 80% to 125% for log-transformed data and Shuirmann and Anderson Hauck tests showed a high probability that area under the curve values for the test product were within 80% to 125% (P < .05). Adverse events occurred at similar rates for the 2 formulations (8 for each product), headache being the most prevalent. The results suggest that the 2 sildenafil formulations, orally disintegrating films and film-coated tablets, are similar in terms of bioavailability, making the test product a good alternative to treat erectile dysfunction and improving dosing convenience.

Keywords: bioavailability; crossover study; erectile dysfunction; pharmacology; sildenafil.