title: Simultaneous determination of cyproterone acetate and ethinylestradiol in tablets by derivative spectrophotometry.
abstract: Derivative spectrophotometry offers a useful approach for the analysis of drugs in multi-component mixtures. In this study a third-derivative spectrophotometric method was used for simultaneous determination of cyproterone acetate and ethinylestradiol using the zero-crossing technique. The measurements were carried out at wavelengths of 316 and 226 nm for cyproterone acetate and ethinylestradiol respectively. The method was found to be linear (r2>0.999) in the range of 0.5-6 mg/100 ml for cyproterone acetate in the presence of 35 microg/100 ml ethinylestsradiol at 316 nm. The same linear correlation (r2>0.999) was obtained in the range of 10-80 microg/100 ml of ethinylestradiol in the presence of 2 mg/100 ml of cyproterone acetate at 226 nm. The limit of determination was 0.5 mg/100 ml and 10 microg/100 ml for cyproterone acetate and ethinylestradiol respectively. The method was successfully applied for simultaneous determination of cyproterone acetate and ethinylestradiol in pharmaceutical preparations without any interferences from excipients.
authors.affiliation: Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Research Center, Tehran University of Medical Sciences, Tehran (14155-6451), Iran. souri@sina.tums.ac.ir
authors.forename: Effat
authors.initials: E
authors.lastname: Souri
authors.forename: Hassan
authors.initials: H
authors.lastname: Jalalizadeh
authors.forename: Hassan
authors.initials: H
authors.lastname: Farsam
authors.forename: Roksana
authors.initials: R
authors.lastname: Ghadiri
authors.forename: Massoud
authors.initials: M
authors.lastname: Amanlou
mesh_terms: D002138:Calibration; D017373:Cyproterone Acetate / Q000032:analysis*; D004355:Drug Stability; D004997:Ethinyl Estradiol / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013607:Tablets / Q000737:chemistry*
chemical_list: D013607:Tablets; D004997:Ethinyl Estradiol; D017373:Cyproterone Acetate