title: Simultaneous determination of enalapril maleate and hydrochlorothiazide by first-derivative ultraviolet spectrophotometry and high-performance liquid chromatography.
abstract: Two methods are described for the simultaneous determination of enalapril maleate and hydrochlorothiazide in combined pharmaceutical tablets. The first method depends on first-derivative ultraviolet spectrophotometry, with zero-crossing and peak-to-base measurement methods. The first-derivative amplitudes at 224 and 260 nm were selected for the assay of enalapril maleate and hydrochlorothiazide, respectively. The second method is based on high-performance liquid chromatography on a reversed-phase column using a mobile phase of acetonitrile-water (20:80, v/v) (pH 3.8) with programmable detection at 215 and 275 nm. Both methods showed good linearity, precision and reproducibility. The proposed methods were successfully applied to the determination of these drugs in laboratory-prepared mixtures and in commercial tablets.
authors.affiliation: Department of Analytical Pharmaceutical Chemistry, Faculty of Pharmacy, University of Alexandria, Egypt.
authors.forename: A F
authors.initials: AF
authors.lastname: el Walily
authors.forename: S F
authors.initials: SF
authors.lastname: Belal
authors.forename: E A
authors.initials: EA
authors.lastname: Heaba
authors.forename: A
authors.initials: A
authors.lastname: el Kersh
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000032:analysis*; D000959:Antihypertensive Agents / Q000032:analysis*; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D004338:Drug Combinations; D004656:Enalapril / Q000032:analysis*; D006852:Hydrochlorothiazide / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013607:Tablets / Q000737:chemistry
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D004338:Drug Combinations; D012996:Solutions; D013607:Tablets; D006852:Hydrochlorothiazide; D004656:Enalapril