Preparation and Evaluation of Gelatin-Based Disc Matrices for the Delivery of Isoniazid

Abstract

The objective of the present study was to formulate disc matrices based on type B gelatin and to evaluate their potential for use as a vehicle for the delivery of isoniazid. Gelatin hydrogel was prepared in an aqueous solution and subsequently cross-linked with glutaraldehyde. The crosslinked hydrogel was cut into discs and dried under vacuum in a dessicator to form the disc-shaped matrices which were further evaluated for swelling, drug loading and in vitro drug dissolution properties. The effect of varying the duration of cross-linking time on these evaluated properties was similarly evaluated. The results obtained showed that the matrices exhibited significant swelling in simulated gastric fluid (SGF) without pepsin (pH 1.2), simulated intestinal fluid (SIF) without pancreatin (pH 6.8) as well as in water. Increase in cross-linking time resulted in increased swelling of the disc matrices in the different swelling media studied. Loading efficiency was similarly observed to increase with increase in cross-linking time with values ranging from 60 to 95 %. Release of isoniazid from the matrices was higher and more rapid in SIF than in SGF and was sustained for more than 24 h. Drug release from the formulated matrices was found to obey the Higuchi model release mechanism. This study, therefore, suggests that disc matrices based on gelatin hold some potential as a vehicle for the controlled delivery of isoniazid.

Keywords: isoniazid, disc matrices, gelatine, hydrogel, cross-linking

Nigerian Journal of Pharmaceutical Research, Vol. 9 No 1 pp. 1 - 14 (February 2011)