Oral controlled drug delivery systems based on microporous polymers

Abstract

Microporous polypropylene (PP) powder shows excellent properties for tabletting. Oral controlled release delivery systems were made by simply blending with drug and compressing to make both matrix and coated tablets. To prevent wetting problems and food interactions, sodium lauryl sulphate (SLS) was adsorbed prior to tabletting on the surface of the microporous PP. In order to reveal possible dosage form-food interactions a new and simple food interaction model (slight modification of the USP XX paddle method) is proposed to standardize both in vitro and in vivo testing procedures. The PP coated oxprenolol tablets show no food interactions when tested in vitro in the food simulation mixture. The same liquid food was used in the in vivo study. The PP coated oxprenolol tablets were given to six male volunteers with and without the food. The absorption profiles, which were calculated by numerical deconvolution, showed hardly any food interactions in vivo. The absolute bioavailability at 12 hours was 38±19% on an empty stomach and 37±20 for the food experiment. The developed coated tablets are able to control the release of oxprenolol at least 12 hours both with and without concomitant food intake. Their bioavailability is comparable to different OROS formulations of oxprenolol controlled release systems based on microporous PP are not only highly effective ones but also low cost formulation products.