title: Simultaneous determination of melatonin-pyridoxine combination in tablets by zero-crossing derivative spectrophotometry and spectrofluorimetry.
abstract: Two methods have been developed for the analysis of melatonin (M) and pyridoxine hydrochloride (PH) in combination. The first method depends on first- and second-derivative ultraviolet spectrophotometry, with the zero crossing technique of measurement. First-derivative amplitudes at 296 nm and second-derivative amplitudes at 294 and 322 nm are selected for the determination of M and PH, respectively. The second method is based on the native fluorescence of both M and PH, in methanol and 0.1 M hydrochloric acid, respectively, after a preliminary solvent extraction procedure. The relative standard deviation of both methods was less than 2.0%. The two methods have been successfully applied to the determination of both drugs in laboratory-prepared mixtures and in tablets.
authors.affiliation: Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, University of Alexandria, Egypt.
authors.forename: H H
authors.initials: HH
authors.lastname: Abdine
authors.forename: A A
authors.initials: AA
authors.lastname: Gazy
authors.forename: M H
authors.initials: MH
authors.lastname: Abdel-Hay
mesh_terms: D008550:Melatonin / Q000032:analysis*; D011736:Pyridoxine / Q000032:analysis*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013607:Tablets / Q000737:chemistry
chemical_list: D013607:Tablets; D008550:Melatonin; D011736:Pyridoxine