Comparative Aging Studies of Tablets Made with Diabasic Calcium Phosphate Dihydrate and Spray Dried Lactose

Abstract

There are relatively few published reports on the aging of tablets (1-4) and thus, as an extension of previously published work, the aging of compressed tablets (prepared using either dibasic calcium phosphate dihydrate or spray^A dried lactose as matrix) has been investigated over a sixty-five day period. All tablets contained 6% amaranth as a dye tracer, 0.5% magnesium stearate as lubricant and 2.5% sodium alginate as disintegrant. Tablets were prepared by direct compression on a single punch press and stored under three sets of stress conditions: (a) 25°C, 45% relative humidity (RH); (b) 35°C, 60% RH; (c) 45°C, 75% RH.

Tablets were evaluated by appearance (visual and photography); weigh; size; hardness (Erweka); disintegration time (U.S.P.); and dissolution (U.S.P.). A transient mottling phenomenon was evident in both systems under accelerated conditions. Significant weight variations were observed at all temperatures for the dibasic calcium phosphate dihydrate system, while lactose tablets showed only slight changes in weight. Under accelerated storage conditions, hardness appears to be related to disintegration times and dissolution rates with either system. However, it is not a reliable tool at room temperature. In addition, results at accelerated conditions do not appear to be directly related to those obtained at room temperature.