Application of Dual Wavelength Spectro-Photometry and Absorbance Ratio Method in Analysis of Complex Preparations Ⅰ.Determination of Sulfamethoxazole and Trimethoprim in Co-Trimoxazole Tablets

The dual wavelength spectrophotometry and the absorbance ratio method are twospectrophotomotric analytical techniques used in the analysis of binary mixtures. They can accelerate of the analysis of some of pharmaceutical preparations containing two active components.These rapid methods have been used for analysis of co-trimoxazole tablets. Theyare simpler and more accurate than the methods previously used. The standard devi-ation for the average recovery is below 1.3%.