Comparison of the pharmacokinetic characteristics and bioequivalence between two nanosuspension formulations of megestrol acetate in healthy Korean male subjects.

Megestrol is commonly used to address appetite loss, cachexia, and significant weight loss in cancer or acquired immune deficiency syndrome patients. This study aimed to assess the pharmacokinetics and determine the bioequivalence of two orally administered megestrol acetate suspensions (625 mg/5 mL) in healthy Korean male subjects. A randomized, open-label, single-dose crossover study was conducted involving fifty-four healthy male subjects who were randomized into two sequence groups. Each subject received either a test or reference drug formulation of 625 mg/5 mL megestrol acetate with a two-week washout period between treatments. Plasma samples were collected before and up to 120 hours after administration, and their plasma drug concentrations were analyzed using validated liquid chromatography-mass spectrometry/mass spectrometry. The pharmacokinetic parameters were calculated, and bioequivalence was confirmed if the 90% confidence intervals of the geometric mean ratios were within the specified bounds of 80.00% to 125.00%. In total, fifty-two subjects completed the study, contributing to the pharmacokinetic analysis. The 90% confidence intervals for the geometric mean ratios of the test formulation compared to the reference formulation were 93.85% to 108.90% for maximum plasma concentration and 91.60% to 101.78% for area under the concentration-time curve from the point of administration to last time point of blood sampling. Throughout the study, no serious or unexpected adverse events were observed. The pharmacokinetic profiles of both formulations of megestrol acetate (625 mg) were comparable and well tolerated in healthy Korean male adult subjects. The test formulation met regulatory criteria for bioequivalence. Trial Registration: ClinicalTrials.gov Identifier: NCT06147908.