Monday, November 5, 2007 - 5:10 PM

The Effects Of Material And Processing Variables On The Properties Of Formulations

Marcos Llusa, Fernando Muzzio, and Kalyana Pingali. Chemical and Biochemical Engineering, Rutgers University, 98 Brett Road, Piscataway, NJ 08854

There are a number of properties of a solid formulation that play critical roles in the manufacturing process (i.e. flowability), in the safety of the process and in the quality of the final product (i.e. dissolution, tablet hardness). The values of these properties are influenced by a number of variables that we classify into two major sources, the physical (i.e. particle size distribution) and chemical nature of the granular components and the processing history of the materials (i.e. shear rates and strain). Furthermore, properties change in a concurrent manner. The aim of this work is to understand how properties and variables correlate, i.e.; hydrophobicity, flowability, bulk density and electrical charge vs. shear rate, strain and composition. A new technique to measure hydrophobicity is developed. The impact of these three variables on the electrical conductivity of tablets is studied as well. This work has been extended to understand how phenomena that are measured concurrently such as dilation and flowability correlate with changes in the electrical charge and electrical impedance of the formulations. The results show that electrical charge accumulates as a function of strain, and also depends on the type of materials used. The conductivity of tablets also correlates with strain, independently of shear rates, while work is being performed to determine the effect of composition. The hydrophobicity is a function of lubricant content, and also of shear rate and strain.