Physicomechanical and physicochemical characterizations of biexponential compaction process of paracetamol in the presence of talcum-lubricated-MCC

Paracetamol exhibits poor compressibility, poor mechanical performance and very difficult to be tableted alone by direct compression method. In the present study compaction process of paracetamol has been characterized in the presence of microcrystalline cellulose (MCC) after talcum lubrication. Compressibility parameters under tapping related to apparent density were obtained by biphasic linear plots. Compacts were prepared over a compression pressure of 24.5 to 343.2 MPa, and change in apparent density and tensile strength was recorded. Primary rearrangement and the secondary rearrangement were the two major steps clearly observed during particle rearrangement process, and the primary rearrangement packing rate was found faster compared to secondary packing rate in all powder formulations. First step of packing compacted to a greater extent compared to the second step during the entire tapping process. Under applied pressure, density difference due to compaction by particle rearrangement was observed to be very high compared to compaction by plastic deformation in the formulations. Solid bridge formation and mechanical interlocking were found to be more intensified as the MCC amount increased with the consequent increase of mechanical strength of the formulation. Level A correlation has been established between tensile strength and apparent density change at the same pressure. Increased loading of MCC in the compacted tablet also increased drug dissolution.