CHARACTERIZATION OF BI-LAYERED TABLET FOR TREATING HEPATOTOXICITY CAUSED BY ANTITUBERCULAR DRUG FOR THE EFFECTIVE MANAGEMENT OF TUBERCULOSIS.

The proposed study aimed  at  development  and  characterization  of  bi-layered  tablet  for treating hepatotoxicity caused by antitubercular drug for the effective management of tuberculosis. Isoniazid is first line antitubercular drug which acts via inhibiting InhA and KasA genes. Based on its solubility and log P values, drug was found to be hydrophilic in nature. Isoniazid is first line drug due to its high efficacy but major disadvantage associated with this drug is hepatotoxicity. Due to this drawback there are various chances to discontinue the therapy. Hence, to prevent this discontinuation silymarin, a herbal hepatoprotective drug can be used in combination with isoniazid.

  Isoniazid was obtained as white, crystalline powder and its melting point was found to be in 161ºC-164º C range. It has maximum absorbance at 261nm and endothermic DSC peak at 163ºC. Based on solubility profile and log P value, amphiphilic nature of Silymarin was determined. Silymarin was obtained as solid powder with maximum absorbance at 288 nm The drug content of bilayer tablet was estimated by simultaneous estimation method. Bilayer tablet was prepared by using HPMC, Carbopol, and cyclodextrin in optimum concentration. Prepared  bilayer tablet  was  optimized  for  in  vitro  drug release  in  altered  media.  Then  the formulation with higher sustained release was selected for bilayer tablet formulation.

Bilayer tablet was characterized on the basis of different parameters such as hardness, friability, weight variation, drug content and in vitro drug release. Drug release kinetics of silymarin from bilayer tablet was found to be Hixson  Crowell mechanism whereas  INH followed Higuchi diffusion model.

Key words: hepatotoxicity, antitubercular , tuberculosis,  Isoniazid, amphiphilic nature.