SENSITIVE AND VALIDATED SPECTROPHOTOMETRIC METHODS FOR THE DETERMINATION OF PHENYLEPHRINE HYDROCHLORIDE AND PYRIDOXINE HYDROCHLORIDE IN PHARMACEUTICALS USING Ce (IV) AMMONIUM SULPHATE AND N-BROMOSUCCINIMIDE BASED ON REDOX REACTION
A simple, low-cost, sensitive and diversely applicable UV-Visible spectrophotometric methods have been developed for the estimation of drugs i.e, Phenylephrine Hydrochloride (PEH) and Pyridoxine Hydrochloride (PRC). Method A is based on the oxidation of drugs by cerium (IV) (excess) in slightly acidic medium at room temperature and estimating the amount of unreacted Ce (IV) by amaranth dye at 520 nm. Method B is based on the oxidation of drugs by N-bromo succinimide (excess) at room temperature and estimating the amount of unreacted NBS by amaranth dye at 520 nm. Beer’s law is obeyed in the concentration range of (0.5 – 4.5 µg/mL) and (1.5 – 7.0 µg/mL) for PEH and PRC [Method A] and (1.0 – 5.0 µg/mL) and (1.5 – 5.0 µg/mL) for PEH and PRC [Method B]. The limit of detection (LOD) and limit of quantification (LOQ) were reported for both the methods. Both the methods were applied for the determination of PEH and PRC in dosage forms and the results were satisfactory and were comparable with those obtained by the reference methods. The accuracy and reliability of the proposed methods were further ascertained by recovery studies