DISSOLUTION TEST METHOD FOR RIFAMPICIN ISONIAZID FIXED-DOSE FORMULATIONS

A dissolution procedure for a rifampicin-isoniazid combination formula tion, was evaluated using 0.1 N hydrochloric acid solution and 0.4% (w /v) sodium lauryl sulphate solution as dissolution media. Rifampicin a nd isoniazid along with degradation components were chromatographed us ing reversed-phase liquid chromatography on a 10 mum octadecylsilica c olumn using methanol-0.01 M disodium hydrogen phosphate (70:30, v/v; p H 4.6 +/- 0.1) as mobile phase. The detection was carried out at 254 n m. The data obtained indicate that the dissolution medium consisting o f 0.4% (w/v) sodium lauryl sulphate solution is suitable for such a co mbination. The degradation observed in dissolution medium consisting o f 0.1 N hydrochloric acid was 10-23%.