The Effect of Consecutive Batch Processing on Particle Size and Thermal Behavior

Two controlled release formulations (A & B) and one immediate release formulation C were used in this study. Formulations and process parameters are shown in Tables 1 and 2. Formulations A and C were designed to produce large granules and formulation B was designed for small granules. Three batches of approximately 37.5 liters of each formulation were granulated one after the other in a 75-liter high-shear granulator (Vector GMX-75). Mixer blade speed during pre-mix and water infusion times was 210 rpm, and 330 rpm during the wet-mass (or high shear) time. The change in product temperature (DT) during the wet-mass time was monitored. After granulation, a portion of the batch was oven dried overnight at 90°C. The remaining portion was dried with 65°C air using a fluid-bed dryer (Vector FL-M-15) until the product was less than 2.5% moisture content. Sieve analyses were performed to determine the arithmetic mean diameters (D50) for oven and fluid bed dried granules.