Abstract
Background: The objective of this study was to compare the pharmacokinetics and safety between newly developed sildenafil (Please Orally Soluble Film) and sildenafil citrate (VIAGRA$^{(R)}$) after single oral administration in healthy Korean male subjects. Methods: A randomized, open-label, single dose, 2-way crossover study was conducted in 50 healthy male subjects. Each sequence group consisted of 25 subjects, received a single oral 50 mg dose of Please Orally Soluble Film (test formulation) or VIAGRA$^{(R)}$ (reference formulation) by study period. Blood samples were obtained during a 24-hour period after dosing. Sildenafil and its metabolite concentrations were determined using validated LC-MS/MS. A non-compartmental pharmacokinetic analysis was performed. Safety was assessed through monitoring of adverse events, vital sign check-up, physical examination, laboratory tests and electrocardiography. Results: All enrolled participants completed the study. The point estimates and 90 % confidence intervals of log transformed $C_{max}$ and $AUC_{last}$ of the test formulation in comparison to those of reference formulation were 0.9294(0.8353 - 1.0341) and 0.9415 (0.8869 - 0.9994) respectively. The analysis of variance showed no significant influences of formulation, sequence and period on the pharmacokinetic parameters. The frequencies of adverse events were not statistically different between the formulations. No serious adverse event was observed or reported. Conclusion: Please Orally Soluble Film could be considered bioequivalent to VIAGRA$^{(R)}$ and had similar safety properties in healthy Korean male subjects.
