Assessment of tableting properties using infinitesimal quantities of powdered medicine.

In the early stage of new drug candidate development, the available quantity of drug substance is limited. In order to carry out preformulation studies of tablets in this stage, a static compression test was carried out with infinitesimal quantity of powder sample using the new Micro Powder Characterizer device. Aspirin, phenacetin, ascorbic acid and ethenzamide were used as model drugs. In this study, the possibility of use of the Micro Powder Characterizer as a device for estimating the tableting properties of each powder sample such as stress displacement curves, tablet tensile strength, stress relaxation rate, and ejection energy was evaluated. In addition, the differences between the Micro Powder Characterizer and the traditional large-scale compression testing machine were compared. It was found that tableting properties could be estimated by the Micro Powder Characterizer, and that the quantity required to estimate tableting properties was approximately 10 mg per measurement. The results were nearly equal to those obtained with the traditional large-scale compression testing machine. This technique thus appears to be useful for early-stage preformulation studies of new drug candidates.