Formulation, characterization and in vitro evaluation of theophylline-loaded Eudragit RS 100 microspheres prepared by an emulsion-solvent diffusion/evaporation technique

Jelvehgari, Mitra, Barar, Jaleh, Valizadeh, Hadi, Shadrou, Sanam and Nokhodchi, Ali (2011) Formulation, characterization and in vitro evaluation of theophylline-loaded Eudragit RS 100 microspheres prepared by an emulsion-solvent diffusion/evaporation technique. Pharmaceutical Development and Technology, 16 (6). pp. 637-644. ISSN 1083-7450

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Abstract

The aim was to prepare theophylline-loaded Eudragit RS 100 microsphere to achieve sustained release pattern with relatively high production yield. To this end, microspheres were prepared by oil/oil solvent evaporation method using an acetone-methanol mixture and liquid paraffin system containing aluminum tristearate. Drug release profiles were determined at pH 1.2 and 7.4. Morphology and solid state of microspheres were examined using SEM, DSC, X-ray powder diffraction (XRPD), and FT-IR. As the ratio of acetone/methanol increased during the preparation of microspheres the size of microsphere was reduced. The highest drug loading efficiency (87.21%) was obtained for the microsphere containing a high ratio of polymer to drug (6:1) and high volume of acetone. SEM studies showed that the microspheres are almost spherical with a few pores and cracks at surfaces. The FT-IR, XRPD and DSC results ruled out any chemical interaction between theophylline and Eudragit. The microspheres prepared with low ratio of polymer to drug (1:2) showed faster dissolution rate than those with high polymer to drug ratio. The ratio of polymer to drug and the volume of polymer solvent were found to be the key factors affecting the release profile which could lead to microspheres with desired release behavior. © 2011 Informa Healthcare USA, Inc.

Item Type: Article
Schools and Departments: School of Life Sciences > Chemistry
Subjects: Q Science > QD Chemistry
Depositing User: Tom Gittoes
Date Deposited: 18 Dec 2014 13:37
Last Modified: 18 Dec 2014 13:37
URI: http://sro.sussex.ac.uk/id/eprint/51776
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