title: Spectrophotometric determination of phenylephrine HCl and orphenadrine citrate in pure and in dosage forms.
abstract: A simple and rapid spectrophotometric methods have been estimated for the microdetermination of phenylephrine HCl (I) and orphenadrine citrate (II). The proposed methods are based on the formation of ion-pair complexes between the examined drugs with alizarine (Aliz), alizarine red S (ARS), alizarine yellow G (AYG) or quinalizarine (Qaliz), which can be measured at the optimum lambda(max). The optimization of the reaction conditions is investigated. Beer's law is obeyed in the concentration ranges 2-36 microgram ml(-1), whereas optimum concentration as adopted from Ringbom plots was 3.5-33 microgram ml(-1). The molar absorptivity, Sandell sensitivity, and detection limit are also calculated. The correlation coefficient was >/=0.9988 (n=6) with a relative standard deviation of </=1.7, for six determinations of 20 microgram ml(-1). The proposed methods are successfully applied to the determination of drugs I and II in their dosage forms using the standard addition technique.
authors.affiliation: Faculty of Science, Chemistry Department, Benha University, Benha, Egypt. alefab@yahoo.com
authors.forename: S A
authors.initials: SA
authors.lastname: Shama
mesh_terms: D002626:Chemistry, Pharmaceutical; D004304:Dosage Forms; D009966:Orphenadrine / Q000032:analysis* / Q000737:chemistry; D010656:Phenylephrine / Q000032:analysis* / Q000737:chemistry; D013051:Spectrometry, Gamma / Q000379:methods
chemical_list: D004304:Dosage Forms; D010656:Phenylephrine; D009966:Orphenadrine