Influence of process parameters on pellets elaborated in a Mi-pro high-shear granulator.

The aim of the study was to prepare porous pellets several hundred micrometers in diameter into or onto which drug substances could be embedded. Wet granulation was carried out on a powder mix of alpha-lactose and polyvinylpyrrolidone in a Mi-Pro high-shear granulator. The process parameters were investigated to point out their influence on pellet physical properties. The reference conditions of granulation that gave the most satisfactory pellets in size and shape were determined by adjusting the volume and the distribution rate of water. Increasing impeller speed resulted in an increase in granule size and granulation yield and in a decrease in proportion of fines. The granules showed easy flowing for all granulation conditions. Adjusting process parameters enabled control of size, shape, surface area, and porosity of the granules and thus the design of ready to use granules to which drug substances could be associated by deposition or inclusion.