Simultaneous determination of Xipamide and Triamterene by first derivative, ratio difference, and derivative ratio spectrophotometric methods

Abstract

Validated, rapid, and sensitive spectrophotometric techniques were established for the simultaneous determination of Xipamide and Triamterene. The first technique is based on the determination of Triamterene with zero-crossing of Xipamide using the zero-order method at 367.0 nm. The second technique is based on the determination of both Xipamide and Triamterene by the first derivative method with zero-crossing of Triamterene and Xipamide respectively, at 265.6 and 388.6 nm. The third technique is the ratio difference spectrophotometric method depending on obtaining peak amplitude difference at 256.0 and 273.0 nm for Xipamide and 288.0, 302.0 nm for Triamterene. The fourth method is the derivative ratio spectrophotometric method depending on obtaining the first derivative of the ratio spectrum with zero-crossing of Xipamide and Triamterene at 365.2 and 308.6 nm; respectively. Linear relationship was obtained upon using concentration range (1.0-10.0 µg/mL) for Xipamide and (1.0-16.0 µg/mL) for Triamterene with LOD less than 0.3 µg/mL for both drugs. The suggested spectrophotometric techniques showed Lower LOD and more sensitivity other than any reported spectrophotometric methods and were applied in pure and dosage form (Epitens®).