SIMULTANEOUS QUANTITATIVE ANALYSIS OF OLMESARTAN MEDOXOMIL AND AMLODIPINE BESYLATE IN PLASMA BY HPTLC TECHNIQUE

Sapan K. Shah*, Dinesh P. Kawade, Alpana J. Asnani and Dinesh R. Chaple

ABSTRACT

A rapid, simple and sensitive high-performance thin layer liquid chromatography (HPTLC) method has been developed for quantification of olmesartan medoxomil (OLM) and amlodipine besylate (AM) in plasma. The assay enables the measurement of OLM and AM for therapeutic drug monitoring with a minimum detectable limit of 2 ng mL−1. The method involves simple, one-step extraction procedure and analytical recovery was above 85-98 %. The separation was performed on silica gel 60 F254. The mobile phase was a mixture of chloroform: methanol: acetic acid in the ratio 7.5: 1.25: 0.2 v/v/v at optimum wavelength selected was 254 nm. The calibration curve for the determination of drugs in plasma was linear over the range 2-200 and 2-800 ng spot−1 for AM and OLM. The coefficients of variation for inter-day and intra-day assay were found to be less than 15%. The method can be applied to pharmacokinetic study of OLM and AM in combined dosage form.

Keywords: Olmesartan medoxomil, Amlodipine besylate, HPTLC, Plasma etc.