Drying rates of tablet granulations II: effect of particle size and granular densities.

The effects of the granule size and density on the drying rate kinetics of tablet granulations were studied using lactose and sulfathiazole granules prepared with acacia mucilage and providone solution. The drying rate kinetics consisted of three distinct phases of drying when the drying rate was platted against remaining moisture content: constant rate, first falling rate, and second falling rate periods. The effect of various statistical diameters and granular density on the drying rate during the first falling rate period was analyzed, and the mechanism of moisture migration during this phase of drying was identified.