A simple, specific, accurate, precise and reproducible method has been developed and validated for the simultaneous estimation of Rifampicin and Isoniazid in combined dosage form by UV Spectrophotometric method. UV spectrophotometric method includes simultaneous equation method using 337.0 nm and 263.0 nm λmax of both the drugs were selected for estimation of Rifampicin and Isoniazid respectively. Rifampicin and Isoniazid follow Beer’s law over the concentration range of 5-35 μg/ml and 5-25 μg/ml. The percentage recoveries of the both the drugs were found to be nearly 100 % representing the accuracy of the proposed methods. Validation of the proposed methods was carried out for its accuracy, precision, and specificity according to ICH guidelines. The proposed method can be successfully applied in routine laboratory analysis for the determination of Rifampicin and Isoniazid in combined dosage form
