ESTIMATION OF AMLODIPINE BESYLATE AND IRBESARTAN IN PHARMACEUTICAL FORMULATION BY RP-HPLC WITH FORCED DEGRADATION STUDIES
International Journal of Applied Pharmaceutics
Objective: To develop and validate a simple, specific, accurate, precise and sensitive reverse phase high performance liquid chromatographic (RP-HPLC) method with forced degradation studies for the simultaneous estimation of amlodipine besylate and irbesartan in the pharmaceutical formulation. Methods: The chromatographic separation of the two drugs were achieved using Enable C 18G column (250 ×4.6 mm; 5 µm) in isocratic mode with mobile phase consisting of sodium acetate buffer (pH 4.0) and
... tonitrile (30:70, % v/v) with a flow rate of 0.6 ml/min. Ultraviolet(UV) detection was carried out at 238 nm. The proposed method was validated for linearity, range, accuracy, precision, robustness, limit of detection (LOD) and limit of quantification (LOQ). The tablet formulation was subjected to stress conditions of degradation including acidic, alkaline, oxidative, thermal and photolysis. Results: The retention time for amlodipine besylate and irbesartan were found to be 5.512 and 6.321 min respectively. Linearity was observed over a concentration range 4-32 µg/ml for amlodipine besylate (r2 =0.9999) and 10-70 µg/ml for Irbesartan (r2 =0.9998). The % relative standard deviation (RSD) for Intraday and Interday precision was found to be 0.436 and 0.699 for amlodipine besylate and 0.435 and 0.30 for irbesartan. Amlodipine besylate shown stability towards acidic and thermal whereas in basic, oxidative and photolytic it shown less stability in which it degraded to more extent. Irbesartan shown stability towards thermal conditions whereas in remaining conditions it degrades to more extent especially in oxidative conditions. Conclusion: The developed reverse phase high performance liquid chromatographic (RP-HPLC) method was also found to be simple, precise and sensitive for the simultaneous determination of amlodipine besylate and irbesartan in the tablet dosage form.