Acta Pharm. 59 (2009) 13-24
Original research paper
RP-HPLC-DAD method for determination of
olmesartan medoxomil in bulk and tablets exposed to forced conditions
RITESH
N. SHARMA and SHYAM S. PANCHOLI
riteshn.sharma@gmail.com
S.
K. Patel College of Pharmaceutical Education and Research, Ganpat University,
Kherva-382711, Gujarat, India
Accepted January 14, 2010
A simple, sensitive and precise
RP-HPLC-DAD method was developed and validated for the determination of
olmesartan medoxomil (AT-II receptor blocker) in the presence of its
degradation products. Olmesartan medoxomil and all the degradation products
were resolved on a C18 column with the mobile phase composed of
methanol, acetonitrile and water (60:15:25, V/V/V,
pH 3.5 by orthophosphoric acid) at 260 nm using a photodiode array detector.
The method was linear over the concentration range of 1–18 µg mL‑1
and precise with RSD < 1% in intra- and inter-day study. Excellent
recoveries of 99.3 ± 0.9 to 100.8 ± 1.2 % proved
the accuracy of the method. Developed method was specific, as indicated by chromatographic
resolution > 2.0 for each peak and sensitive with LOD 0.03 µg mL−1 and LOQ 0.1 µg mL−1. The method was used to study the
drug degradation behavior under forced conditions. Four degradation products
(DP-I, II, III, IV) were formed during the degradation study in 0.1 mol L−1
HCl whereas only DP-I, II and III were formed in water, 0.01 mol L−1
NaOH and 3 % H2O2. No
significant thermal or photolytic degradation was observed in solid drug.
The method was applied successfully for the assay of olmesartan medoxomil in the
tablet dosage form.
Keywords: olmesartan medoxomil, forced
degradation, high performance liquid chromatography, stability