Analytical Methodologies for Determination of Methylcobalamin: An Overview

Three different form of vitamin B12 are available as methylcobalamin, cyanocobalamin and hydroxocobalamin. Methylcobalamin is considered as an active form of vitamin B12 whereas other two as inactive forms. Methylcobalamin is official in Japanese Pharmacopoeia. This article reviews the analytical methods for identification and quantitative estimation of methylcobalamin in various pharmaceutical formulations. We had reviewed analytical methods published so far for estimation of methylcobalamin in pharmaceutical formulations mainly from 1960 to 2015. The most commonly adopted method for the determination of methylcobalamin was UV–Visible spectrophotometry. There were various other methods reported viz Reversed Phase - High Performance Liquid Chromatography (RP-HPLC), Thin Layer Chromatography (TLC) and liquid chromatography coupled with tandem mass spectrometry. Almost all methods have been developed for estimation of methylcobalamin in tablet (available as combination with another drug). There was a single method reported for quantitative estimation of methylcobalamin injection.