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A J Moës

Publications and source records attributed to A J Moës.

25 records · Page 2Linked to original sources
PubMedDate not supplied

Influence of additives on the release profile of nifedipine from poly(DL-lactide-co-glycolide) microspheres.

Nifedipine-containing poly(DL-lactide-co-glycolide) (PLGA) microspheres of various sizes and drug contents were prepared by the solvent evaporation method. The in vitro release profiles of nifedipine from PLGA microspheres and the degradation pattern of the polymer were evaluated. Four additives were incorporated in the microspheres: two non-fatty plasticizers: diethylphthalate and triacetin, and two fatty substances: isopropyl myristate and Myvacet. Diethylphthalate and Myvacet increased the nifedipine release rate while isopropyl myristate and triacetin had no influence on it. Triacetin seems to be very poorly incorporated into the microspheres. These additives did not modify the degradation rate of the polymer. Differential scanning calorimetry detected a decrease of the glass transition temperature of diethylphthalate-containing microspheres, a small variation with Myvacet, and very little change when triacetin or isopropyl myristate were incorporated. This variation of the glass transition temperature (Tg) tends to imply that nifedipine is released by a diffusion process through the polymer matrix which is enhanced when additives decrease the Tg. Scanning electron microscopy allowed the vizualization of the highly porous structure of microspheres containing the oily substances, and the unchanged smooth surface of diethylphthalate-containing microspheres.

Biocompatible Materials↗
PubMedDate not supplied

[Research and development of oral controlled-release dosage forms].

Important data concerning the gastrointestinal transit of oral solid dosage forms have been obtained recently by using the technique of gamma scintigraphy. It is now possible to put forward the principal limitations of the oral sustained release dosage forms actually available. The research and development of new controlled release products such as buoyant dosage forms and coevaporates with polymers should permit to decrease the large inter and intrasubject variations of drug plasma levels observed when the actual sustained release dosage forms are administered.

Administration, Oral↗