Simultaneous Determination of Atenolol and Chlorthalidone in Tablets by Wavelet Transform Methods

Erdal DİNÇ *°, Ebru SAYGEÇİTLİ*, Zehra Ceren ERTEKİN*

* Ankara University, Faculty of Pharmacy, Department of Analytical Chemistry, 06100 Tandoğan, Ankara, Turkey

° Corresponding Author;
Phone: +90 312 203 31 76
Fax: +90 312 213 10 81
E-mail: dinc@ankara.edu.tr

 

Summary

In this paper two graphical methods based on Coiflet 5 continuous wavelet transform (COIF-CWT) and Mexican Hat function continuous wavelet transform (MEXH-CWT) were developed and applied to the UV absorption spectra of binary mixtures containing atenolol (ATE) and chlorthalidone (CHL) in the presence of strongly overlapping signals. In order to obtain appropriate transformation of UV spectra of analyzed compounds, several values of scaling parameter (a) were tested. The optimal values of the scale parameters were found to be a= 120 for COIF-CWT and a=128 for MEXH-CWT. In the CWT applications, calibration curves for ATE and CHL were found to be linear in the range of 20-120 μg/mL and 15-60 μg/mL, respectively. An algorithm written in Matlab 7.10 was used for the one dimensional wavelet analysis. The validation of the mentioned signal processing methods was performed by analyzing various binary mixtures of ATE and CHL. The proposed signal processing methods were then applied to the analysis of commercial tablets. The methods presented in this paper are rapid, easy, inexpensive and do not need any separation process or preliminary treatments for the analysis of the overlapping UV spectra of ATE and CHL in their samples.

Key Words :
Drug analysis, chemometrics, wavelet transform, spectrophotometry, atenolol, chlorthalidone.