Development and Validation of Stability Indicating Mass Compatible RP-HPLC Method for Simultaneous Estimation of Assay and Related Substances in Methylprednisolone Acetate Injectable Suspension

Abstract

A new stability indicating mass compatible RP-HPLC method was developed and validated for the simultaneous estimation of assay and related substances of methylprednisolone acetate (MPA) in methylprednisolone acetate injectable suspension. Chromatography was carried out with C18 column (100 mm × 4.6 mm, 3.5 μ particle size) with an isocratic elution of mobile phase composed of 1 g/L Ammonium acetate and Acetonitrile in the ratio of 67:33 v/v at a flow rate of 1.5 mL/min. The column oven temperature was maintained at 50 ºC and the detection was carried out using UV detector at 254 nm. Validation parameters such as system suitability, specificity (matrix interference and forced degradation), linearity, precision, accuracy, limit of detection (LOD), limit of quantitation (LOQ), solution stability and robustness were performed according to ICH guidelines. The retention time for MPA was about 7 min. Methylprednisolone acetate (MPA) and its impurities were well separated from each other. The percentage mean accuracy of MPA was found to be 99.1% for assay and ranged from 101.4% to 104.8% for known impurities. The % relative standard deviation (RSD) for the six replicate assay results was found less than 1%. The method is linear in the range from 0.2 μg/mL to 600 μg/mL (i.e. 0.05% to 150% of the test concentration). The correlation coefficient for linearity was found to be greater than 0.999 for MPA and its impurities. Limit of detection and limit of quantification was demonstrated to be 0.017%w/w and 0.05%w/w, respectively. The validated method is simple, mass compatible, fast, specific, stability indicating, accurate, linear, precise, rugged, sensitive and robust.