MODELING THE PLASMA DRUG LEVEL WITH ORAL CONTROLLED-RELEASE DOSAGE FORMS WITH LIPIDIC GELUCIRE

The plasma drug level is evaluated in the case of oral dosage forms wi th prolonged release when the matrix is made of lipidic Gelucire. From in vitro studies, the process of drug release follows a typical patte rn: the liquid dissolves the drug in contact with it and thus, enters the dosage form, enabling the drug to diffuse out of the dosage form t hrough the liquid located in it. The diffusivity of the drug increases with the concentration of the liquid in an exponential way. The kinet ics of drug release out of the dosage forms fit the experimental resul ts obtained with in vitro experiments perfectly. The plasma drug level is obtained with aspirin as the drug, by using a numerical model taki ng into account the kinetics of release of the drug out of the dosage form and the pharmacokinetic parameters. The effect of the dimensions of the dosage forms on the plasma drug level is considered. (C) 1998 E lsevier Science B.V. All rights reserved.