Relative bioavailability of four clomipramine hydrochloride tablet products.

The relative bioavailability of clomipramine was determined in two single-blind, single-dose, randomized, crossover studies. In the first study, the relative bioavailability of the test product, 2 x 25 mg clomipramine hydrochloride tablets (Noristan Ltd.), with respect to the reference product, Anafranil® 2 x 25 mg tablets (clomipramine HCl ; Ciba-Geigy (Pty) Ltd.) was determined. In the second study, the relative bioavailability of the test product, 5 x 10mg clomipramine hydrochloride tablets (Noristan Ltd.), with respect to the reference product, Anafranil® 5x10 mg tablets (clomipramine HCl ; Ciba-Geigy (Pty) Ltd.), was determined. The geometric mean values for the variable C max were 31.3 ng mL -1 for the reference and 31.6 ng mL -1 for the test product in study 1. The geometric mean values for the variable AUC were 736 ng h mL -1 and 753 ng h mL -1 for the reference and test, respectively. In study 2, the geometric mean C max values were 25.8 ng mL -1 and 23.9 ng mL -1 for the reference and test respectively ; the geometric mean AUC values were 569 ng h mL -1 and 547 ng h mL -1 . The 90% confidence intervals for the 'test/reference' mean ratios of the plasma clomipramine pharmacokinetic variables C max and AUC (0- ∞ ) (as measures of the rate and extent of absorption of clomipramine, respectively) fall within the conventional bioequivalence range of 80-125% for both studies. The test products (clomipramine HCl) are therefore bioequivalent to the reference products (Anafranil®) with respect to the rate and the extent of absorption of clomipramine in both 10 mg and 25 mg strengths.