Abstract

Iffath Rizwana¹, K. Vanitha Prakash^2*, G. Krishna Mohan³

DOI : http://dx.doi.org/10.13005/ojc/310131

A new, simple, precise, accurate and reproducible RP-HPLC method for simultaneous estimation of minoxidil and aminexil in bulk and pharmaceutical formulations. Separation of  minoxidil and aminexil was successfully achieved on a Agilent C18 (150 mm x 4.6 mm x 5µ Make: Waters) or equivalent in an isocratic mode utilizing 0.1% orthophosphoric acid and methanol in the ratio of 60:40 v/v at a flowrate of 1 ml/min. The developed method was found to be linear in the concentration range of 50µg/ml to 150 µg/ml for minoxidil and 50 µg/ml to 150 µg/ml for aminexil. The value of the correlation coefficient was found to be 0.999 for both minoxidil and aminexil. The LOD and LOQ for aminexil were found to be 0.0146 and 0.0486 mg/ml, respectively, where as for minoxidil the values are 0.046 mg/ml and 0.155 mg/ml, respectively. This method was found to be good percentage recovery for minoxidil and aminexil were found to be 99.00 and 100.00, respectively indicates that the proposed method is sufficiently accurate. The specificity of the method shows good correlation between retention times of standard with the sample. Therefore, the method specifically determines the analyte in the sample without interference from excipients that are commonly present in the pharmaceutical dosage forms. The method was validated according to ICH guidelines for linearity, range, accuracy, precesion, specificity and robustness.

RP-HPLC; Minoxidil; Aminexil

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