The present study aim was to formulate and evaluate the bilayer tablets containing Rifampicin immediate release layer (IR) and isoniazid in the sustained release (SR) layer in the way to develop a single tablet containing two different layers of drugs as widely used by physician and have better patient compliance. The SR layer of Isoniazid was developed by the method of wet granulation and using the grade of HPMCK100m, and other excipients like lactose, magnesium stearate, microcrystalline cellulose & talc. The IR layer of Rifampicin was developed by the method of direct compression. The powders are characterized by pre formulation properties and tablets are characterized by post formulation properties. The in-vitro study of Rifampicin and Isoniazid using USP(type 2) dissolution apparatus. The release rate studied for 45 mins by using 0.1M HCL and phosphate buffer PH 6.8 for 2hrs absorbed by UV spectrophotometry. Rifampicin release rate from the formulations was more than 80% at 45 min by adding HPMCK100m. Total three batches of each drug have been manufactured and developed stable formulation, the stability studies was complied as per International Conference of Harmonization guidelines.

Keywords : HPMC, IR,SR,ICH Guideline, UV Method , USP.