Simultaneous Estimation of Amlodipine Besylate and Indapamide in a Pharmaceutical Formulation by a High Performance Liquid Chromatographic (RP-HPLC) Method

Abstract

An isocratic reversed-phase liquid chromatograpic assay method was developed for the quantitative determination of amlodipine besylate (AML) and indapamide (IND) in combined dosage form. A Brownlee C-18, 5 μm column with a mobile phase containing 0.02 M potassium dihydrogen phosphate-methanol (30+70, v/v) total pH-adjusted to 3 using o-phosphoric acid was used. The flow rate was 1.0 mL min(-1) and effluents were monitored at 242 nm. The retention times of amlodipine besylate and indapamide were 5.9 min and 3.6 min, respectively. The proposed method was validated with respect to linearity, accuracy, precision, and robustness. The method was successfully applied to the estimation of amlodipine besylate and indapamide in combined tablet dosage forms.

Keywords: Amlodipine; Indapamide; RP-HPLC; Tablet; Validation.

Fig. 1

Structure of amlodipine besylate (AML) and indapamide (IND)

Fig. 2

HPLC chromatogram of IND (RT 3.6 min) and AML (RT 5.9 min), using 0.02 M KH₂PO₄-methanol (30+70, v/v) total pH adjusted to 3 using O-phosphoric acid as mobile phase