Biodisponibilidad de cuatro preparados de teofilina de liberación sostenida del mercado nacional / Bioavailability of 4 sustained release teophylline preparations

We evaluated pharmacokynetic parameters and bioavailability of 4 sustained release teophylline preparations. A crossover design was used in 12 healthy males aged 22 to 27 years old. each individual recived 250 mg iv followed by 250 mg orally of each preparation, and then 400mg rapid acting aminophylline. A 7 day period was allowed between drug courses. HPLC was used to determine plasma levels of teophylline at regular intervals up to 48 hr following drug administration. Significant (p < 0.05) differences in pharmacokynetic parameters were found among preparations, 2 of them having larger integrals of plasma levels and one of them different times to peak plasma level and peak plasma concentration, compared to both remaining preparations

Carbamazepina: biodisponibilidad de cuatro productos farmacéuticos orales / Bioavailability of carbamazepine from 4 products

The bioavailability of carba,azepine from 4 comercially available products was evaluated in 12 healthy volonteers. A crossover design was used and each patients received 400 mg of each product. Plasma levels of the drug were determined periodically for 72 h using a gas-liquid chromatographic method. An open model of one compartment for first-order absortion was assumed to derive pharmacokinetic parameters. Dissolution kinetics was also evaluated in each product. Significant differences in biovailability were shown for one product. Results correlated with the in vitro dissolution findings