Pharmacokinetics and comparative bioavailability of domperidone suspension and tablet formulations in healthy adult subjects

Domperidone is a dopamine antagonist with a unique gastroprokinetic and antiemetic properties. This study was conducted to evaluate the pharmacokinetics (PKs) and comparative bioavailability of suspension (reference) and tablet (test) formulations of domperidone. In vivo study was established according to a single-center, randomized, single-dose, laboratory-blinded, two way, cross-over study with a washout period of 1 week. Under fasting conditions, 26 healthy Egyptian male volunteers were randomly allocated to receive a single oral dose of either 20 mL domperidone or two tablets (each contains 10 mg domperidone) of marketed suspension and tablet formulations. Plasma samples were obtained over a 24-hour interval and analyzed for domperidone by reversed phase liquid chromatography with fluorescence detection. The 90% confidence intervals for the ratio of log transformed values of Cmax , AUC0-t , and AUCt-∞ of the two treatments were within the acceptable range (0.8-1.25) for bioequivalence. From PK perspectives, in this small study in healthy Egyptian adult male volunteers, a single 20 mg dose of the tablet formulation was bioequivalent to a single 20 mg dose of the suspension formulation based on the US FDA's regulatory definition. No adverse events occurred or were reported during the study and both formulations were well tolerated.