Effect of drying phase on the agglomerates prepared by spherical crystallization

Abstract

In this paper, differences in porosity, compressive strength and tablet- forming ability of carbamazepine crystals agglomerated under similar condition, but subjected to different drying temperatures are reported. The agglomerates were prepared by spherical crystallization method and thereafter dried without agitation at different temperature. An increased drying temperature did not affect the shape and structure texture of dried particles and did not cause them to fracture. Drying of particles at higher temperature suppressed the particle contraction as a consequence of fast evaporation and hence produced particles of larger mean diameter, higher porosity and thus lower compressive strength than those dried at lower temperature. Through a relationship with particle porosity, the drying rate also affected the ability of particles to form tablets.

Keywords: Agglomerates; Carbamazepine; Drying; Tabletting.

Figure 1

SEM photographs of the agglomerates dried with the highest (a) and the lowest (b) drying rate constant.

Figure 2

The distribution histograms of the agglomerates dried at different temperatures