title: Utility of 4-chloro-7-nitrobenzofurazan (NBD-CI) for the Spectrophotometric and spectrofluorometric determination of several antihistamine and antihypertensive drugs.
abstract: New, sensitive, and selective spectrophotometric and spectrofluorometric methods have been developed for determination of clemastine hydrogen fumarate (Clem), loratadine (Lor), losartan potassium (Los), and ramipril (Ram) in both pure form and pharmaceutical formulations using 4-chloro-7-nitrobenzofurazan (NBD-CI), which is a highly sensitive chromogenic and fluorogenic reagent. The relation between absorbance at 470, 467, 471, and 469 nm and the concentration was linear over the ranges 5-35, 10-100, 10-90, and 10-120 microg/mL for Clem, Lor, Los, and Ram, respectively. The complexation products were also measured spectrofluorometrically at the emission wavelength 535 nm for Clem, Lor, and Ram and at 538 nm for Los with excitation at 477 and 452 nm for Clem and Lor, respectively, and 460 nm for both Los and Ram. The fluorescence intensity was directly proportional to the drug concentration over the ranges 0.05-0.5, 5-20, 1-6, and 2-15 microg/mL for Clem, Lor, Los, and Ram, respectively. The methods were successfully applied for the determination of the studied drugs in pharmaceutical dosage forms with excellent recovery.
authors.affiliation: Wake Forest University, Department of Chemistry, Winston-Salem, NC, and Zagazig University, Faculty of Pharmacy, Department of Analytical Chemistry, Zagazig, Egypt. soadselem@yahoo.co.uk
authors.forename: El-Hay Soad S
authors.initials: el-HS
authors.lastname: Abd
authors.forename: Christa L
authors.initials: CL
authors.lastname: Colyer
authors.forename: Wafaa S
authors.initials: WS
authors.lastname: Hassan
authors.forename: Abdalla
authors.initials: A
authors.lastname: Shalaby
mesh_terms: D009327:4-Chloro-7-nitrobenzofurazan / Q000737:chemistry*; D000959:Antihypertensive Agents / Q000032:analysis*; D002974:Clemastine / Q000032:analysis*; D006634:Histamine H1 Antagonists / Q000032:analysis*; D017336:Loratadine / Q000032:analysis*; D019808:Losartan / Q000032:analysis*; D017257:Ramipril / Q000032:analysis*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013053:Spectrophotometry / Q000379:methods*
chemical_list: D000959:Antihypertensive Agents; D006634:Histamine H1 Antagonists; D017336:Loratadine; D002974:Clemastine; D009327:4-Chloro-7-nitrobenzofurazan; D019808:Losartan; D017257:Ramipril