HPLC-PDA identification and resolution of rufinamide forced degradation impurities: A congregated chemometric expedite optimization coupled with factorials and desirability

Rufinamide is used presently to treat Lenaux-Gastaut syndrome. A full factorial design and desirability approach was investigated for the optimization of hydrolytic stress via response surface curves (RSCs). The degradation impurities were identified and resolved using reversed-phase high-performance liquid chromatography (RP-HPLC) on the Qualisil (R) BDS C-8 column. Acetonitrile-water (29:71, v/v) was optimized for the mobile phase and used at a flow rate of 1.0 ml/min with detection at a wavelength of 230 nm. Rufinamide showed appreciable susceptibility to hydrolysis under acidic and alkaline stress, and substantial degradation in the neutral condition. It degraded much less under oxidative stress. Exposure towards thermal and photolytic stress conditions indicated appreciable stability. The developed method was subjected to validation as per the recommendations of the International Conference on Harmonization. The proposed method showed no influence from the excipients and the degradation products. As well as good precision and accuracy in determination, the method showed a linear response between 2 and 12 mu g ml(-1). The method was extended for determination in a human plasma sample, which resulted in excellent recovery without interference from matrix effects. The combined use of desirability and design for the optimization of acidic and alkaline hydrolytic stress led to simple and rapid analysis.

Automated summary

This study investigated the optimization of hydrolytic stress for Rufinamide using a full factorial design and desirability approach. Reversed-phase high-performance liquid chromatography was used to identify and resolve the degradation impurities. The developed method showed good precision, accuracy, and no interference from excipients or degradation products.