A VALIDATED GRADIENT STABILITY-INDICATING LC METHOD FOR THE ANALYSIS OF VALSARTAN IN PHARMACEUTICAL DOSAGE FORM
TRIPTI SHARMA, SUDAM CHANDRA SI
International Journal of Pharmacy and Pharmaceutical Sciences
Objective: The objective of this research work was to develop a sensitive, precise, specific, linear and stability-indicating gradient HPLC method for the estimation of valsartan in bulk drug and in pharmaceutical preparations. Methods: Chromatographic separation was achieved on C-18 stationary phase with a gradient mobile phase consisting of orthophosphoric acid buffer (the pH of the solution was adjusted to 4.2±0.05 with triethylamine) and methanol. The eluent was monitored with PDA detector at 225 nm with a flow rate of 1.0 ml/min, run time of 65 min. Results: The method was linear over the range of 20-120μg/ml. The correlation coefficient was found to be 0.9994±0.02. In order to check the selectivity of the method for pharmaceutical preparations, forced degradation studies were carried out. Valsartan was found to be stable at light and oxidation experiments. The performance of the method was validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision and robustness. .The LOQ was found to be 0.26µg/ml and the LOD was found to be 0.79µg/ml. Valsartan showed good correlation coefficient in the concentration range of 20-120μg/ml. The developed method was compared statistically by applying two-way anova and student's t-test to correlate with an isocratic method and was applied to bulk drug and tablet dosage form. There was no significant difference between the two methods. Conclusion: The proposed method was found to be accurate, precise, sensitive and robust. Hence, it can be used successfully for the routine analysis of valsartan in pharmaceutical formulation and for analysis of stability samples obtained during accelerated stability study.
HPLC, Valsartan, Degradation products, Pharmaceutical dosage forms, Two-way ANOVA and student's t-test