VALIDATED CHROMATOGRAPHICAL METHODS FOR THE SIMULTANEOUS ESTIMATION OF ANTIHYPERTENSIVE DRUGS IN PHARMACEUTICAL DOSAGE FORMS

Delhiraj N* and Anbazhagan S

Two new, rapid, precise, accurate and specific chromatographic methods for the simultaneous determination of Olmesartan medoxomil,Amlodipine besylate and Hydrochlorothiazide in combined pharmaceutical dosage forms. The first method based on reverse phase liquid chromatography by using Qualisil BDS C18 column (250 mm X 4.6 i.d., 5 μm). Mobile phase consists of 1.0 ml of triethylamine in one litre water and the pH was adjusted to 2.5 with orthophosphoric acid and Acetonitrile (60:40) with a flow rate of 1ml/min, with a detection wavelength of 231nm.The second method involved silica gel 60F254 high performance thin layer chromatography and densitometric detection at 231 nm using chloroform: methanol (85:15) as the mobile phase.