Olmesartan Medoxomil (OLME) belongs to a group of angiotensin II receptor
blockers used as an antihypertensive agent and is currently being used for
prevention of Hypertension. This paper describes the Validation and
development of stability indicating RP-HPLC method for the determination of
OLME in the presence of its degradation products generated from forced
degradation study and characterization of degradation product (impurity). The
assay involved gradient elution of OLME on An LC GC BDS C18 column (250 ?
4.5mm, 5-?m particle size) was employed for loading the sample. The mobile
phase A consists of 7 ml Triethylamine in 1000 ml water (pH adjusted to 3.0
with orthophosphoric acid) and B contains acetonitrile. Quantification was
achieved with photodiode array detection at 257 nm. The chromatographic
separation was obtained with a retention time of 6.72 min, and the method was
linear in the range 50-150 ?g/ml. The method was validated according to the
ICH guidelines with respect to linearity, precision, accuracy, limit of
detection (LOD), limit of quantification (LOQ), specificity and robustness.
Impurity found in stressed and stability studies of Olmesartan Medoxomil in
both drug substance and drug product are described. This degradation product
is identified as 1-(biphenyl-4-ylmethyl)-1H-imidazole-5-carboxylic acid. An
Alkaline degradation pathway of Olmesartan medoxomil, for the formation of
this degradation product, has been proposed and degradation product was
characterized.
Stability-Indicating Methods for Determination of Pyritinol Dihydrochloride in the Presence of Its Precursor and Degradation Product by Derivative Spectrophotometry