Development and Validation of HPTLC Method for the Simultaneous Estimation of Amlodipine Besylate and Atorvastatin Calcium in Combined Dosage Form

Abstract

This present study reports for the first time simultaneous quantitation of Amlodipine
besylate and Atorvastatin calcium by HPTLC from a combined dosage form.
Chromatographic separation of the drugs were performed on aluminum plates
precoated with silica gel 60 F254 used as stationary phase and the chromatogram was
developed using Ethyl acetate: Methanol: Ammonia (7.5 : 2 : 0.5 %v/v/v) as mobile
phase. Amlodipine besylate and Atorvastatin calcium showed Rf values 0.50 ± 0.02 and
0.26 ± 0.02 respectively. Densiometric analysis of both the drugs was carried out in the
absorbance mode at 365 nm. The method has been successfully applied to tablets and
was validated according to ICH Harmonized Tripartite guidelines. The linearity
regression analysis for calibration showed 0.9983 (r2) and 0.9994 (r2) for amlodipine
besylate and atorvastatin calcium with respect to peak area and height in the
concentration range of 100-500ng/spot and 200-600ng/spot respectively. The
percentage recovery for amlodipine besylate was found to be 101.82 (at 50%), 99.12 (at
100%) , 100.5(at 150%) and 101.41 (at 50%), 101.71 (at 100%), 99.5(at 150%) for
atorvastatin calcium. The limit of detection was 30 ng/spot and 60 ng/spot for
amlodipine besylate and atorvastatin calcium respectively. The limit of quantification
was found to be 100 ng/spot and 200 ng/spot for amlodipine besylate and atorvastatin
calcium respectively. The developed TLC technique is precise, specific and accurate. It
was concluded that the developed method offered several advantages such as rapid, cost
effective, simple mobile phase and sample preparation steps and improved sensitivity
made it specific, reliable and easily reproducible in any quality control set-up providing
all the parameters are followed accurately for its intended use.