Preferred orientation of crystalline particles within tablets. III. Change in degree of preferred orientation of aspirin crystals during compression (author's transl)

Abstract

The degree of preferred orientation of aspirin crystals in a tablet as a function of compression force was measured using the X-ray diffraction method. Preferred orientation took place during compression and the degree was affected by the size and morphology of the crystals. Thin, plate-like crystals had the strong tendency to orient preferentially at an early stage of compression, while pulverized crystals oriented gradually at over 100 kg/cm2 of the compression force. In addition, volume, specfic surface area, pore size distribution and breaking strength of the tablets were measured and the relationship among these factors was investigated.