In vivo study of sustained-release formulations containing amoxicillin and Gelucire 64/02

Formulations prepared by fluid-bed coating of direct acting granules with Gelucire 64/02 have shown adequate sustained-release properties in vitro. The in vivo study described demonstrates that the amount of unaltered amoxicillin excreted via urine decreases progressively as the ability of the formulations to sustain release increases. No differences are observed in MRT or VRT. The results obtained show the presence of an absorption window for this aminopenicillin. An assessment is made of the topographic representations proposed by various authors to predict the in vivo behaviour of controlled-release formulations and also potential problems in the bioavailability.