Investigation of Related Impurities in Metadoxine by a Reversed Phase High Performance Liquid Chromatography Technique.

A new reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed for the separation and identification of impurities present in metadoxine. Herein, we report that one of the impurities eluted from the metadoxine sample is 4-deoxypyridoxine hydrochloride (4-DPH). In HPLC analysis, the retention time (RT) of 4-DPH was observed to be at 13.