Simultaneous spectrophotometric determination of cyproterone acetate and ethinyl estradiol in tablets using continuous wavelet and derivative transform

In this study a zero crossing technique based on continuous wavelet transform (CWT) as well as classical derivative spectrophotometry (CDS) is presented for simultaneous determination of cyproterone acetate and ethinyl estradiol in binary mixtures and commercial dosage of drug, without using prior chemical pre-treatment. Absorption spectra were recorded in the wavelength range 200-400 nm. Absorbance data were subjected to various mother wavelets from continuous wavelet transform family to find the optimum point of the wavelet signal processing (Matlab 7.5) gaus 15 and morl wavelet functions with scaling factor, a = 70 and 3rd derivative with Δλ = 10 nm, were selected. Optimum value of scaling factor was chosen to obtain an appropriate calibration for each method. The validation of proposed methods was investigated by several synthetic mixtures and obtained results were successfully compared among each other. Mean recovery values were found between 96.93% and 101.7% for CWT and 95.55% and 104.22% for DS, respectively for the determination of cyproterone acetate and ethinyl estradiol in synthetic mixtures. The developed methods are rapid, precise and easy to apply for the analysis of overlapping signals of the components in the mixtures. Obtained results from the CWT were compared to those yielded by CDS which were in good agreement and therefore led to a successful determination.