Novel preparation of free flowing spherically granulated dibasic calcium phosphate anhydrous for direct tabletting

Abstract

Free flowing spherically granulated (average diameter, 70 or 115 μm) dibasic calcium phosphate anhydrous (DCPA) for direct tabletting was prepared by a restricted crystal growing synthesis of DCPA, followed by spray drying of its aqueous dispersions. The spherically granulated DCPA had larger specific surface area (32 to 34 m2/g), because they had porous structures composed of very fine primary crystals (Heywood diameter, 0.1-1.0 μm) compared to conventionally prepared DCPA (Heywood diameter, 2.0-5.0 μm). The crystallinity of granulated DCPA was lower than that of conventional DCPA. Those micromeritic characteristics of granulated DCPA might correlate closely with their dramatically improved tablettability.