摘要：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 mg 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 mg mL-1 and LOQ 0.1 mg 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 and3%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.
