Two simple and accurate spectrophotometric methods were presented for the determination of binary mixtures of each of Eprosartan and Irbesartan with Hydrochlorothiazide in dosage forms. Concerning the first mixture (Eprosartan/Hydrochlorothiazide mixture), Eprosartan was assayed by first derivative zero crossing technique, while Hydrochlorothiazide was determined by the second derivative zero crossing technique after extraction with ethyl acetate. On the other hand, for the second mixture (Irbesartan/Hydrochlorothiazide mixture), Irbesartan was determined by the first derivative zero crossing technique after extraction with chloroform, while Hydrochlorothiazide was determined by a specific colorimetric method using chromotropic acid.
The aim of this work was to provide new analytical methods for both mixtures. These methods proved to be accurate and precise and were highly able to cope with the strong spectral interference of the binary mixture components, without any interference from the other component or from the excipients. They were rapid and did not require any sophisticated apparatus if compared to HPLC and capillary electrophoresis methods. Therefore, the proposed methods can be used for the routine analysis of both mixtures in quality control laboratories.
Derivative spectrophotometry, Zero crossing technique, Twocomponent mixture, Pharmaceutical analysis
