Use of an orthogonal function in differential spectrophotometry

Abstract

An orthogonal function method has been applied to the differential spectrophotometric determination of acetazolamide and hydrochlorothiazide in tablets. The error resulting from setting the wavelength scale during the application of the orthogonal function to conventional spectrophotometry is thereby minimised. The results of assay using the proposed method [p_2(r) method] are more precise than those obtained with the p₂ method.