Spectrophotometric Estimation Of Melatonin And Pyridoxine Hydrochloride In Combined Dosage Forms
Simple colorimetric methods for the estimation of melatonin and pyridoxine hydrochloride in combined dosage form are described. Estimation of melatonin in presence ot pyridoxine hydrochloride is based on oxidative coupling reaction using 3-methylbenzothiazolin-2-one hydrazone (MBTH) and cerric ammonium sulphate. The reddish colored melatonin complex is measured at 530 nm against reagent blank it obeyed linearity over 1.2 to 15.6 Âµg/ml. Pyridoxine hydrochloride is estimated using ferric nitrate and 1,10-phenanthroline producing reddish brown colored chromogen, measured at wavelength of maximum absorption 510 nm against reagent blank. The chromogen obeyed linearity over 12.0 to 32.0 Âµg/ml for pyridoxine hydrochloride in presence of melatonin.