To characterize dry powder properties and evaluate difference between wet and dry microcrystalline cellulose (MCC 102) granules formed by various grades of PVP (KollidonRTM) as granulating agent using rheological and thermal tools

Powders are used so extensively throughout the pharmaceutical industry, they are amongst the most difficult materials to characterize. Most commonly faced problems are flowability and content uniformity or weight variation, that depending upon whether the material is highly aerated or consolidated. These problems may attribute to poor flow of powder from hopper to the die or segregation of the powders in the hopper. All traditional methods of flowability assessment provide only a relative measure, we needed is an instrument for characterising flow properties.;Wet granulation is a common unit operation in the pharmaceutical and chemical industries, used to improve flowability and reduce segregation. End point determination of wet granulation process always remains a challenge. Though, there are many traditional methods available for end point determination, accuracy and reproducibility is always a challenge. Rheological and thermal property of a material is a very useful tool for determination of end point of wet granulation.;The aim of this study was to investigate the critical end point of wet granulation using freeman technology-4 (FT-4) rheometer and effusivity sensor probe. Microcrystalline cellulose 102 (Avicel PH102) was used as model powder and soluble grades of Kollidon (PVP) as a binder to investigate behavior of granules formed during and after granulation. Each batch was individually granulated with 15%w/w solution of three different soluble grades of Kollidon in ethanol. In rheological characterization, End point of wet granulation was determined by flow properties by measuring Basic Flowability Energy (BFE), Specific Energy (SE), Compressibility and Pressure Drop (PD) using rheometer. Thermal analysis was performed by Differential scanning colorimetry (DSC), to study absorption and glass transitions characteristic of Avicel PH102. The granules were formed with increasing amount of liquid binder until the end point was reached. Effusivity data also suggested a dramatic increase in effusivity reading at the end point for wet granules. Dried granules were characterized by FT-4 rheometer and effusivity to measure various parameters. Particle size analysis and granule fracture strength of dried granules were also performed.