Simultaneous Spectrophotometric Determination Of Rifampicin, Isoniazid And Pyrazinamide By First-Derivative UV Spectrophotometry In Combined Pharmaceutical Dosage Forms
A rapid and simple method for the simultaneous determination of rifampicin (RIF), Isoniazid (INH) and pyrazinamide (PYZ) by first-derivative UV spectrophotometry has been developed in combined pharmaceutical dosage forms. RIF is determined by measuring the signal at Zero crossing point for INH and PYZ (262.2 and 268.8 nm), INH is determined from the signal at the zero crossing point for RIF and PYZ (254.0 and 268.8 nm) and PYZ is determined from the signal at zero crossing point for INH and RIF (262.2 and 254.0 nm) respectively. Good linearity, precision and reproducibility were found. The proposed method was successfully applied to the determination of drugs in physical mixture and formulation.