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The design and construction of a laboratory size dryer and other accessories suitable for investigating the drying rate kinetics of granules under controlled external conditions are described. Granulations of lactose and sulfathiazole, representing water‐soluble and insoluble materials, were prepared using various commonly used binders, and their drying rates were determined. The binders and diluents affected the drying rate curves for these granulations both qualitatively and quantitatively. Granules made with starch paste and gelatin solution required maximum time and energy for drying and those made with simple syrup USP required the least among the binders studied. Generally, three linear slopes were observed when the drying rate was plotted against the moisture remaining, indicating that granulation drying may be considered as occurring through three distinct phases.

Experimental granulations were produced using aqueous and alcoholic solutions of polymeric celluloses, vinyls, acrylamides, pyrrolidones, oxazolidinones, and ethylene oxide condensation products. Products were compared to control formulations granulated with starch paste. Dextroamphetamine sulfate was employed in a preliminary dialysis and dissolution study in the presence of the polymers shown to be of value. The experimental products exhibited gloss equal or superior to coated tablets in many instances, and no drug binding or inhibition of release occurred. The polymer-bound granulations displayed excellent flow properties, were easily compressed into tablets of various degrees of hardness, were generally more resistant to friabilation than the control; some of the polymers produced tablets which had equal or superior disintegration times compared to the control.

An unusual occurrence of decreasing tablet disintegration time with increasing tablet hardness was explored. Tablets were made with varying ratios of starch disintegrant to starch paste and compressed with eight different forces. This unusual disintegration pattern is modified by changes in the starch ratios. The reason for this phenomenon is ascribed to grain swelling as the mechanism by which starch acts as a disintegrant.