Effect of drug properties on the release from CAP microspheres prepared by a solvent evaporation method

• Type: Article in International Scientific Journal
• Date: 1999

Authors

Sousa e Silva, J.P (Author) FFUP; M. Ferreira J. P. (Author) Other

Journal

Title: Journal of Microencapsulation

Vol. 16 No. 1

Pages: 95-103

ISSN: 0265-2048

Publisher: Taylor & Francis

Indexing

ISI Web of Knowledge - 15 Citations

Scopus - 16 Citations

Scientific classification

FOS: Medical and Health sciences > Other medical sciences

Other information

Authenticus ID: P-001-5X3

DOI: 10.1080/026520499289347

Abstract (EN): Drugs with different water-solubility and molecular weights were microencapsulated in cellulose acetate phthalate, using an emulsion-solvent evaporation technique with a continuous oil-phase. The mean size of the particles was approximately 600 mu m, and they were non-porous. The capacity of the microspheres to retain the drugs was evaluated by in nu iota tro release studies in acidic medium. For low molecular weight compounds the release rates increased with solubility: for thiamin hydrochloride and phenacetin, a highly and a poorly soluble compound respectively, the percentages released at 60 min were 90 and 10%. Drugs with molecular weights above approximately 700 Da were retained in the microspheres. The above dependence on solubility was corroborated by release studies in ethanol, and by modelling the release of phenacetin in acidic media. Microspheres with a different polymer matrix, Eudragit(R) RS PO, were also prepared by a similar technique, and these particles prolonged the release of thiamin for over 6 h, under simulated GI conditions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9