Determination of Niacinamide in Pharmaceutical Preparations

Abstract

A method for the isolation of niacinamide from multi-component pharmaceutical preparations by partition chromatography between a diatomaceous earth-water column and chloroform followed by measurement of UV absorbance at 262 mμ is proposed. A second method using the color produced by the niacinamide in the column eluate with bromothymol blue in chloroform is also proposed to allow measurements in the visible range. The chromatographic separation is specific for niacinamide and the procedures are simple and rapid. However, alcohol modifies the partition between water and chloroform, causing the niacinamide to be eluted early. The SD of the UV absorbance method is 0.5% and of the bromothymol blue method is 1.7%. The precision of the proposed UV absorbance method compares favorably with that of the Pelletier and Campbell method and gives values approximately 2% higher.