An improved ion chromatographic method for fast and sensitive determination of N-methylpyrrolidine in cefepime hydrochloride.

An alternative ion chromatographic method to the existing USP method for the determination of N-methylpyrrolidine (NMP) in cefepime hydrochloride is developed. The cefepime in solution behaves as a strong cation and gets retained in the analytical column, leading to reduction in column capacity and irreproducible retention time. The retained drug has to be removed with a special rinsing solution, followed by re-equilibration with the mobile phase.

Ion chromatographic determination of residual phase transfer catalyst in active pharmaceutical ingredient.

A new ion chromatography method with non-suppressed conductivity detection has been developed for the quantification of residual phase transfer catalyst-tetrabutylammonium bromide (TBAB) in an active pharmaceutical drug, Levetiracetam. Separation conditions are optimized to get a clear separation of TBAB from drug impurities using a Metrosep Cation C2-150 column. Conditions are also optimized to separate tetramethylammonium bromide, tetraethylammonium bromide, and tetrapropylammonium bromide, which are also used as phase transfer catalysts in several syntheses.