A Novel Stability Indicating RP-HPLC Method for Simultaneous Quantification of Serdexmethylphenidate and Dexmethylphenidate in Fixed Dosage Form.

A simple, robust stability indicating RP-HPLC method was developed for simultaneous quantification of serdexmethyl phenidate and dexmethyl phenidate in a fixed capsule dosage form. This is the first method to be reported for simultaneous estimation and quantification of degradation products produced from forced stressing of the dosage form as per ICH guidelines. The chromatographic separation was attained on Waters X-terra C18 column using a mixture of trifluoro acetic acid and acetonitrile (70:30 v/v) as mobile phase with a flow rate of 1 mL, monitored at 265 nm over a run time of 10 min. Serdexmethyl phenidate and dexmethyl phenidate were eluted with retention times of 2.71 min and 7.33 min, respectively. The method displayed linear responses in the range of 4.2-63 μg/mL (0.9994) for serdexmethyl phenidate and 0.9 to 3.5 μg/mL (0.9998) for dexmethyl phenidate, respectively. The percentage recoveries of the two drugs were found within the acceptable limits. Forced degradation was conducted and showed considerable degradation in various stress conditions. It also confirms the specificity of the method as no interference peaks were observed concerning for to stress products. This method can be routinely used in quality control labs for simultaneous determination of respective drugs in marketed dosage form.