Stability Indicating UV-Spectrophotometric Methods for Simultaneous Determination of Losartan Potassium and Hydrochlorothiazide in Pharmaceuticals

Abstract

Two new stability indicating UV-Spectrophotometric methods have been described for the simultaneous assay of
Losartan Potassium and Hydrochlorothiazide in bulk drug and in tablet dosage forms using 0.01 N HCl as the
solvent. Method A is based on simultaneous equation or Vierodt’s method and Method B is Q-analysis or Qabsorbance ratio method. The λmax values for Losartan Potassium and Hydrochlorothiazide in the solvent
medium were found to be 227.4 nm, 270.4 nm and 256.4 nm, 270.4 nm for Method A and Method B
respectively. The systems obey Beer’s law in the range of 2.02-22.22 µg mL-1
, 3.03-27.27 µg mL-1 and 5.05-
50.50 µg mL-1
, 3.03-27.27 µg mL-1
for Losartan Potassium and Hydrochlorothiazide for Method A and Method
B respectively. Repeatability, Intra-day and interday precision were found to be 0.202 and 0.670, 0.566-1.31,
0.608- 1.35 for Method A and 0.989 and 0.586, 0.561-1.30, 0.602- 1.33 for Method B. No interference was
observed from common tablet adjuvants. t –test and F-test have been applied for the recovery studies of the two
methods. The changes in the λmax values (Physical parameter) for Losartan Potassium and Hydrochlorothiazide
was evaluated as for stability study. The methods were successfully applied to the assay of Losartan Potassium
and Hydrochlorothiazide in tablet formulations.