Abstract

A two way, randomized cross-over bioequivalence study was conducted to comparing the rate and extent of absorption of two formulations of tadalafil tablets after a single dose of 20mg. The study was carried out using healthy male volunteers (N=29) under fasting conditions. A highly sensitive liquid chromatography-tandem mass spectrometry method was developed and validated, which was employed to determine the tadalafil in human plasma. Phoenix Win Nonl in 8.0 was used for pharmacokinetic analysis and bioequivalence between the two Tadalafil Tablets was determined by calculating 90% confidence intervals (90% C.I.) for the ratio of Cmax, AUC0-t and AUC0-∞ values for the test and reference products. The 90% confidence intervals for the ratio of Cmax (87.60-101.01%), AUC0-t (89.98-104.55%) and AUC0-∞ (89.45-104.03%) values for the test and reference products. These values were within the acceptable range of 80.00%-125.00%, proposed by FDA. It was concluded that there was no significant difference between the rate and extent of absorption of the two Tadalafil Tablets.