(245d) Characterization of Powders

In pharmaceutical solid dosage manufacturing processes such as tableting (compaction), fundamental powder properties are not well understood. This hinders design of formulation and a predictive scale-up of solid dosage manufacturing processes. The fundamental powder properties governing these unit operations are time-dependent visco-elastic properties of the formulation and powder material. The time-dependent visco-elastic properties of commonly used pharmaceutical powders were measured using dynamic mechanical analyzer. The effect of material properties, binary mixtures, solid fraction, and humidity was investigated on the dynamic mechanical properties of the powder.

The storage modulus of the material increases with the increase in dynamic frequency, solid fraction, and decrease with the increase in moisture. The loss modulus remained constant for the range of frequency evaluated. For binary mixtures, the storage modulus increases as the fraction of elastic material increases. These measurements indicate that dynamic mechanical properties can serve as a fundamental properties of pharmaceutical powder mixtures.

Dynamical mechanical properties should allow for a design and optimization of the pharmaceutical formulation and a predictive scale-up of the pharmaceutical processes.