, vol. 4, issue 1, pp. 345 - 356, 2013.
Two RP-HPLC and TLC methods were developed and validated according to the
ICH guidelines for the simultaneous determination of Amlodipine, Valsartan and
Hydrochlorothiazide in tablet dosage form. The two methods are simple, rapid and
selective. Complete HPLC separation was achieved using Nucleosil C18 column and
acetonitrile/methanol/isopropyl alcohol (55:41:4 by volume) mixture as the mobile
phase, the pH was adjusted to 8 ± 0.1 with triethylamine and the flow rate was 1.2
mL/min. The detection wavelengths were chosen to be 238, 248 and 271 nm for
Amlodipine, Valsartan and Hydrochlorothiazide, respectively. The linearity of the
proposed method was established over the ranges, 2.0–28.0, 10.0–120.0 and 0.6–
32.0 µg/mL for Amlodipine, Valsartan and Hydrochlorothiazide, respectively. For the
densitometric TLC method, silica gel 60 F254 plates were used and ethyl
acetate/toluene/methanol/ammonia (50.5:23.5:23.5:2.5 by volume) mixture as the
developing solvent. Detection and quantification were performed densitometrically at
252 nm. The linearity of the proposed method was established over the ranges, 0.5-
9.0, 4.0-18.0 and 3.0-11.0 µg/band for Amlodipine, Valsartan and
Hydrochlorothiazide, respectively.
