Simultaneous Chromatographic Determination of Multi Drug Components in Fixed Dose Combination Tablets Containing Olmesartan, Hydrochlorothiazide and Amlodipine

Background: A number of pharmaceutical companies manufacture fixed-dose combination tablets containing Olmesartan, Hydrochlorothiazide and Amlodipine, while few analytical methods are available for simultaneous determination of the three compounds. The existing methods are more time consuming and possess less sensitivity. Objective: The objective of the study was to develop a sensitive, precise and accurate reverse phase high performance liquid chromatographic method for simultaneous quantification of olmesartan, hydrochlorothiazide and amlodipine in tablet dosage form and validate it as per international regulatory guidelines. Methodology: The analytes were separated using a C-18 (25cm×4.6mm, 5mm) reverse phase column using mobile phase consisting of tri-ethylamine in water adjusted to pH 2.75 with o-Phosphoric acid and Acetonitrile (69:31) (Buffer: ACN) v/v pumped at a flow rate of 1.0 mL/min with an injection volume of 20µl. Results: Linearity was found within the range 8.05-60.42 µg/mL (R2=0.9991) for olmesartan, 4.99-37.46 µg/mL and for hydrochlorothiazide (R2=0.9980) and 1.98-14.87 µg/mL for amlodipine (R2=0.9997). The system suitability parameters as well as robustness were found acceptable with %RSD < 2.0. The percentage recovery of three analytes was 98.841 ± 0.401, 99.672 ± 0.563 and 98.865 ± 0.521 at 100% of nominal concentration for olmesartan, hydrochlorothiazide and amlodipine respectively. Conclusion: A new UV-HPLC based analytical method for simultaneous quantification of Olmesartan, Hydrochlorothiazide and Amlodipine has been successfully developed and and validate it according to international regulatory guidelines. The method can be effectively applied for the assay of tablets in pharmaceutical QC labs.