The objective and timing of drug disposition studies, appendix V. A comparison of the bioavailability of three dosage forms of terfenadine.

Antagonistic effect against histamine-induced wheals was used to evaluate the bioavailability of terfenadine in monkeys. A rapidly dissolving tablet formulation of terfenadine shows essentially identical bioavailability to a liquid suspesion. A less readily dissolving capsule formulation lags considerably in time with regard to availability, and some question remains as to whether the total quantity in the capsule is available.