A stability indicating simultaneous dual wavelength UV–HPLC method for the determination of potential impurities in fampridine active pharmaceutical ingredient

A novel, sensitive, stability indicating simultaneous dual wavelength reverse phase UV–HPLC method has been developed for the quantitative determination of potential impurities of fampridine active pharmaceutical ingredient. Efficient chromatographic separation was achieved on a C18 stationary phase in gradient mode and quantitation by ultraviolet dual wavelength detection. The method was validated according to ICH guidelines with respect to specificity, precision, linearity and accuracy. Regression analysis showed correlation coefficient value greater than 0.999 for fampridine and its seven impurities. Detection limit as low as 0.003% was achieved for fampridine N-oxide and 0.01% for other impurities. Accuracy of the method was established based on the recovery obtained between 93.3% and 110.0% for all impurities. The method was found to be specific, selective to the degradation products and robust. Peak purity analysis by PDA detector confirmed the specificity of the method. Major degradation of the drug substance was found to occur under oxidative stress conditions to form fampridine N-oxide.

► Fampridine is a new generation potassium channel-blocking agent.
► It is being used to improve the walking speed in patients with multiple sclerosis.
► This is the first drug approved by USFDA in this therapeutic category.
► We discuss a HPLC method for the determination of potential impurities.
► LC–UV method is novel, sensitive and stability indicating.