To study the effect of different molecular weights of polyvinylpyrrolidone (PVP) as binder, on end-point of wet granulation of microcrystalline cellulose (MCC) and evaluate the wet and dried granule properties using thermal and rheological techniques

Pharmaceutical powders and their blends exhibit poor flow properties and compaction behavior due to a wide range of physicochemical and mechanical properties like particle size, size distribution, density and surface area. Very Fine powders have poor flow properties due to the excess of air entrapped and therefore they do not compress to make a good tablet. Thus, granulation an intermediate step is usually required in solid dosage forms manufacturing to make the product flow free with better compression properties. Granulation is done by many techniques in Pharmaceutical Industries but due to the convenience of handling and wide application with high and very low dose drugs wet granulation is the method of choice for many formulators. Adding a binder in the granulating liquid has become common practice in recent years due to its advantages. A binder is included in the formulation to increase particle cohesion and to improve tablet hardness and reduce friability. Binders play an important role with respect to technology as well as biodisponibility.;The main aim of this study was to evaluate the effects of chemical and physical properties of binder solution, like molecular weight and viscosity on the end-point of wet granulation and rheology of granules. Microcrystaline cellulose (MCC) is the most commonly used diluent and Polyvinyl pyrrolidine (PVP) is the most commonly used binder. Two grades of PVP (K17PF and K25) mainly differing in molecular weights were evaluated as a binder to prepare granules. Determination of end-point is a critical step in wet granulation since less amount of liquid will not bind the particles strongly and reduce yield while over granulation will result in larger granules which will create challenge in compression and later steps of formulation. Thermal effusivity C-therm technology and FT4 powder rheometer were used for the evaluation of end-point.;Another major problem faced is the flow properties of granules. Many traditional methods like angle of repose, Carr's Index, Haussner's Ratio, Tapped density and bulk density have been used for rheological studies. Freeman Technology has introduced an accurate method which not only evaluate the flow properties also helps in predicting the wet granulation end point. Where Basic Flowability Energy (BFE) and Stability Index(SI) data can be used in choosing end point.;It was observed that although both the binders showed almost similar end point i.e. 55%w/w but the granules did show difference in other properties like Flow Energy, Permeability, Aeration, Compressibility , Particle Size distribution and strength of the granules because of effect of molecular weight or viscosity of the binder solution.