(031) Bioequivalence Studies of Sildenafil Citrate Orodispersible Film Administered With and Without Water versus Viagra Film-Coated Tablets in Healthy Adult Male Volunteers
Authors: Shaw A , Lawrence T E , Yan T , Liu M S , Summers N , Daggumati V , Austria S T , Rondon J C , Hackley S , Vignesh S O , Hassan T 
Published: March 2024

Abstract

Introduction
Orodispersible film (ODF) formulation offers ease of use, convenience of administration, and other advantages, especially for patients who have difficulty in swallowing or are on liquid restriction compared with conventional oral formulations for the treatment of erectile dysfunction.

Objective
These studies compared the bioequivalence of 50 mg sildenafil citrate ODF formulation (test drug) with the marketed 50 mg sildenafil citrate film-coated tablet (FCT) (Viagra; Pfizer, New York, NY) (reference drug), with and without water in 2 randomized cross-over studies.

Methods
Two randomized cross-over studies were conducted. The first study explored the bioequivalence of test drug administered with and without water compared with the reference drug with water. The second study investigated the bioequivalence of test drug, without water, compared with the reference drug with water. 42 healthy adult male volunteers started the first study and only 40 completed. While 80 subjects who were enrolled completed the second study. All the 120 subjects from both the studies were included for pharmacokinetic and bioequivalence analysis. All volunteers fasted for 10 hours pre-dose. A 1-day washout period between doses was observed. Blood samples were collected at regular intervals both before (up to 120 minutes before dosing) and after dosing (at different intervals up to 14 hours) dosing stages. Statistical analyses on pharmacokinetic parameters were performed. Safety and tolerability for both the formulations were evaluated.

Results
In the first study, bioequivalence was demonstrated for sildenafil citrate ODF administered with water when compared with the Viagra FCT. The ratios of adjusted geometric means (90% confidence interval (CI)) were maximum plasma concentration: 1.02 (94.91–108.78) and area under the plasma concentration-time curve: 1.09 (104.49–113.21) for sildenafil citrate ODF administered with water vs Viagra FCT. These ratios were within the bioequivalence acceptance range of 80% to 125%, indicating that the bioequivalence criteria were met. The pharmacokinetic parameters for the second study also demonstrated bioequivalence for sildenafil citrate ODF when administered without water compared with Viagra FCT. The ratios of adjusted geometric means (90% CI) were maximum plasma concentration: 1.02 (95.47–109.36) and area under the plasma concentration-time curve: 1.06 (103.42–108.40) for sildenafil citrate ODF administered without water vs Viagra FCT. Adverse events in both the studies occurred at similar rates for the 2 formulations and were mild in intensity and were expected from the known safety profile.

Conclusions
Sildenafil citrate ODF administered with and without water met bioequivalence criteria compared with Viagra FCT administered with water under fasted conditions in healthy adult male volunteers. These results suggest that the new ODF formulation can be used interchangeably with the marketed FCT formulation. Therefore, the new ODF formulation can be used as a suitable alternative to the conventional oral solid dosage form for the treatment of ED.

Disclosure
Yes, this is sponsored by industry/sponsor: Viatris Inc.
Clarification: Industry initiated, executed and funded study.
Any of the authors act as a consultant, employee or shareholder of an industry for: Viatris Inc.