ADSORPTION OF ISONIAZID ON INSOLUBLE TABLET EXCIPIENTS AND CHARCOAL

Mesiha, M. S.; Shawky, S.

doi:10.21608/bfsa.1984.89562

ADSORPTION OF ISONIAZID ON INSOLUBLE TABLET EXCIPIENTS AND CHARCOAL

Document Type : Original Article

Authors

M. S. Mesiha ¹
S. Shawky ²

¹ Departments of Industrial Pharmacy, Faculty of Pharmacy, Assiut University, Assiut, Egypt

² Departments of Pharmaceutics, Faculty of Pharmacy, Assiut University, Assiut, Egypt

10.21608/bfsa.1984.89562

Abstract

The adsorption of isoniazid onto the insoluble directly compressible tablet excipients : Emcotmpress, Avicel pH 101, Elcema P 50, P 100, G 250, ethyl cellulose and STA-Rx as well as talc, magnesium stearate and charcoal was studied. The adsorption followed the Langmuir equation over initial concentrations of 80-200 mmole/L of isoniazid solution in water or in buffer solutions of pH 2.1 and 7.2. The adsorption capacities were of the following sequence: charcoal > starch > celluloses and talc > ethyl cellulose > emcompress. No measurable adsorption was noted on magnesium stearate or glassware. The possible mechanisms of adsorption were discussed.
The kinetics of isoniazid release from compressed tablets using Emcompress, Avicel, ethyl cellulose and starch as the excipients did not correlate with the adsorption data, but the extent of release of drug had a good correlation with the adsorptive capacities of the excipients.