title: Study on the charge-transfer reaction between 7,7,8,8-tetracyanoquinodimethane and drugs.
abstract: The charge-transfer (CT) reaction between 7,7,8,8-tetracyanoquinodimethane (TCNQ) as a pi-electron acceptor and cinnarizine, analgin, norfloxacin as electron donors have been studied by spectrophotometric method. The charge transfer complexes between TCNQ and these drugs have stable blue color, therefore a simple, rapid, accurate and sensitive method for determination of these drugs has been developed. The optimization of the experimental conditions is described. Beer's law is obeyed in the ranges 2-18, 2-18 and 4-32 microg/ml for cinnarizine, analgin and norfloxacin, respectively. The apparent molar absorptivity of CT complexes at 743 nm is 1.58x10(4), 1.71x10(4) and 8.91x10(3) l/mol per cm, respectively. The composition of all these CT complexes are found to be 1:1 by different methods. The relative SDs are less than 3% (n = 10). The proposed method has been applied to the determination of these drugs in their each pharmaceutical dosage forms with satisfactory results.
authors.affiliation: Department of Chemistry, Peking University, Beijing, PR China.
authors.forename: Z
authors.initials: Z
authors.lastname: Feng-lin
authors.forename: X
authors.initials: X
authors.lastname: Bian-zhen
authors.forename: Z
authors.initials: Z
authors.lastname: Zhi-quan
authors.forename: T
authors.initials: T
authors.lastname: Shen-yang
mesh_terms: D000096:Acetone; D002936:Cinnarizine / Q000032:analysis / Q000737:chemistry; D004177:Dipyrone / Q000032:analysis / Q000737:chemistry; D004304:Dosage Forms; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry*; D009643:Norfloxacin / Q000032:analysis / Q000737:chemistry; D010084:Oxidation-Reduction; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods*; D013696:Temperature; D013997:Time Factors
chemical_list: D004304:Dosage Forms; D009570:Nitriles; D004364:Pharmaceutical Preparations; D000096:Acetone; C013703:tetracyanoquinodimethane; D002936:Cinnarizine; D004177:Dipyrone; D009643:Norfloxacin