Tensile and Shear Testing of Some Pharmaceutical Powders

Abstract
Twelve pharmaceutical diluents have been characterized by determination of particle size distribution, tensile strength and the shear cell parameters cohesiveness (C), flow factor (FF) and the effective angle of friction (dL). Nine materials possessed a size distribution approximating log-normal. Avicel and the starch samples exhibited highest cohesiveness and lowest flow factors. The correlation between C and FF was good, but T was unrelated to either. Values of C/T varied from 0.19 to 3. 16. It is suggested that in many cases, estimates of T may not fit the yield locus at the corresponding bulk density because of different modes of consolidation in the tensile tester and shear cell.