Objective: To compare the pharmacokinetic profiles and to assess bioequivalence of a newly developed orally soluble film formulation of sildenafil, taken without water, with those of a conventional formulation of sildenafil.
Methods: This study was conducted in a population of healthy subjects as an open-label, randomized sequence, two-period, two-formulation, single-dose, crossover design. The subjects were randomly assigned to 1 of 2 sequences of the two formulations: an orally soluble film (OSF) of 50 mg sildenafil as the test drug and a film-coated tablet (FCT) of 50 mg sildenafil as the reference drug. Blood samples were collected at intervals from 0 to 24 hours after administration. Plasma concentrations of sildenafil and its active metabolite N-desmethyl sildenafil were analyzed using a liquid chromatography/tandem mass spectrometry method.
Results: 48 healthy male subjects completed the study. The geometric mean (CV%) for Cmax in the OSF and FCT formulations were 267.21 (4.68%) ng/mL and 285.97 (5.32%) ng/mL, respectively. The geometric mean for AUClast in the OSF and FCT formulations were 664.48 (4.40%) ng x h/mL and 647.96 (4.63%) ng x h/mL, respectively. The geometric mean for AUCinf in the OSF and FCT formulations were 685.65 (4.37%) ng x h/mL and 666.28 (4.60%) ng x h/ mL, respectively. The 90% confidence intervals of the ratios of the geometric means of the Cmax, AUClast, and AUCinf were 0.844 - 1.030, 0.961 - 1.091, and 0.965 - 1.093, respectively.
Conclusions: The OSF sildenafil formulation exhibited no significant differences in its pharmacokinetics compared with those of the FCT formulation. Therefore this convenient OSF sildenafil formulation, which can be taken without the need for water or chewing, offers physicians a novel and attractive treatment option for men with erectile dysfunction. *These authors contributed equally to this work.