Requirements for the Production of Microtablets: Suitability of Direct-Compression Excipients Estimated from Powder Characteristics and Flow Rates

Abstract

Eleven direct-compression excipients, namely 3 microcrystalline celluloses, 4 lactoses, 4 co-processed excipients, and 4 mixtures of lactoses with Avicel PHI02 SCG were evaluated for possible use in micro tableting. Powder-technological parameters, namely particle size distributions, true and apparent densities, densification behaviour, and mass flow rates from a funnel through very narrow orifices, were determined.

Flow rates required on modern high-speed rotary tableting machines were calculated.

Flow rates may be estimated even for very narrow orifices, and such studies aid in selection of suitable excipients.

Mainly spray-dried lactose preparations with certain, definite upper limits in size distribution, seem to comply with the prerequisites for the production of micro tablets.