Color Stability of Ascorbic Acid Tablets Measured by Tristimulus Colorimeter

Abstract

The influence of three different tableting diluents and three different forms of ascorbic acid on the color change of vitamin C have been investigated. Ten different direct compression formulations were made and subjected to accelerated stability study. Color changes in tablets were monitored with a Tristimulus Colorimeter. It has been found that lactose and Emdex influenced the color change of direct compression ascorbic acid tablets to a lesser degree than Sorbitol. Further, Calcium Ascorbate brought changes in the color of the tablets at a faster rate than C-90 or Sodium Ascorbate. A good correlation of 0.998 was found for a linear relation of visual color rating against normalized total color difference values of these tablets.