DERIVATIVE AND DIFFERENCE SPECTROPHOTOMETRIC DETERMINATION OF CYPROTERONE ACETATE AND ESTRADIOL VALERATE IN FORMULATIONS

Cem Yücesoy*º , Serpil Erol*

*Ankara University, Faculty of Pharmacy, Departemant of Analytical Chemistry, 06100 Tandogan, Ankara, TURKEY.
°Corresponding Author

Summary:
Binary combinations of cyproteron acetate(CA) and estradiol valerate (EV) were determined by first derivate UV spectrophotometry. First derivate absorbance values of the solutions at 269.9 nm and 297.7 nm (for CA) and at 283.1 nm (for EV) were measured against blank. EV was also determined by pH induced difference spectrophometry. Difference absorbance values of the solutions at 245.4 nm were read against blank.Calibration equations of CA and EV were linear over the concentration range of 5-25 ?g/ml and 8-40 ?g/ml, respectively.The recoveries of the drugs from standart mixtures were in both methods between 97.7% and 102.4 %. The precision of the methods for CA and EV were better than 2.12 % and 0.95 % as relative standart deviation, respectively.

Key words:
Cyproterone acetate, Estradiol valerate, Simultaneous determination, Derivative and difference spectrophotometry.