Simultaneous Estimation of Atorvastatin Calcium and Amlodipine besylate by UV Spectrophotometric method using hydrotropic solubilization

Plan: An analytical method for the simultaneous estimation of Atorvastatin Calcium (ATV) and Amlodipine Besylate (AML) by UV spectrophotometry using hydrotropic solubilization is described.Prologue: The method is simple, fast and accurate and can be used for the routine analysis of Atorvastatin and Amlodipine in combination tablets.Methodology: The developed method uses the absorption ratio or Q‐value which is based on the measurement of absorptivity at 293 nm (iso-absorptive point, both the drugs were found to have same absorbance at this wave length) and 247 nm (absorption maximum of one of the drugs, Atorvastatin). Both the drugs are insoluble in water and require corrosive organic solvents for solubilization. Therefore an attempt was made to preclude the use of corrosive solvents by the use of 2M Urea by hydrotropic solubilization method. The calibration curves for both drugs were found to be linear in a concentration range of 10-60μg/mL .Outcome: The proposed method has been applied successfully for the simultaneous determination of Atorvastatin and Amlodipinein pharmaceutical dosage forms. No significant interference was observed from the tablet excipients and 2M Urea used for solubilization. The mean recovery of the drugs from the combination tablets was 100.65%.for Atorvastatin and 101.42% forAmlodipine respectively.Key Words: Amlodipine, Atorvastatin, Spectrophotometry, Tablets.