Assessment of Isoniazid and Pyridoxine Hydrochloride in Pure and Pharmaceutical Preparations

New spectrophotometric method was described for the simultaneous assay of pyridoxine hydrochloride and isoniazid. The method was based on proton transfer reaction between pyridoxine hydrochloride B6 and chromeazurol S at pH = 5.7 to give a red, water soluble product which absorbed at the selective wavelength at 510 nm. By bleaching the red coloured product, pyridoxine hydrochloride –chromeazurol S, this method for determining isoniazid IND was devised. The IND's common side effect is numbness increased blood levels of liver enzymes. The method follows Beer’s law at the range of concentration from 5 to 700 /25ml for pyridoxine hydrochloride (i.e. 0.2-28.0) ppm and molar absorptivity value was 1.51×104 l/mol.cm and from 25 to 1500 /25ml for isoniazid (i.e. 1-60) ppm, the value of molar absorptivity equal to 1.36×104 l/mol.cm., the accuracy (average recoveries) 100.44%, 100.20% of B6 and IND respectively. This study aims to find spectroscopic method for the determination of isoniazid and pyridoxine hydrochloride in their pharmaceutical preparations, So that, this approach has been used to determine pyridoxine hydrochloride and isoniazid in pharmaceutical formulations with great success.