Development and Validation of Isoniazid and Paraamino Salicylic Acid Simultaneously in Prepared Cocrystal Formulation By UV Spectrophotometry

Isoniazid (INH) and Paraamino salicylic acid (PAS) are antitubercular drugs. Three simple, sensitive, precise and economical simultaneous UV spectrophotometric methods have been developed and validated in bulk drugs and its co-crystal formulation. Cocrystals of INH & PAS were prepared by solvent evaporation technique. Methanol was selected as the solvent. Maximum absorption was observed at 263nm and 271nm for INH and PAS respectively. The Method A was based on simultaneous estimation by simultaneous equation method. Method B was based on calculation of Area under Curve (AUC) for the analysis of INH and PAS in the wavelength range of 258-268nm. In Method C, First order derivative spectra of INH and PAS showed a sharp peak at 243 and 257 nm respectively. All the three methods were validated as per ICH guidelines. The proposed methods were applied to estimate the amount of INH and PAS in bulk drug and formulations