Highly compressible paracetamol - II. Compression properties

Paracetamol particles crystallized in the presence of polyvinylpyrrolidone (PVP) exhibited an obvious improvement in their compression properties comp ared to untreated paracetamol. Paracetamol particles crystallized in the pr esence of 0.5% w/v PVP 10 000 or PVP 50 000 produced tablets with improved crushing strength with no tendency to cap even at high compression speeds. The very low values of strain rate sensitivity (SRS) and the lack of reduct ion in crushing strength with increasing compression speed for these partic les, were indicative of a high degree of fragmentation during compression. The results of elastic recoveries and elastic energies of tablets were indi cative of much less elastic behaviour of these particles than untreated par acetamol. The low elastic energy/plastic energy (EE/PE) ratio for paracetam ol crystallized in the presence of PVP indicated that, contrary to untreate d paracetamol, a minor portion of compression energy was utilized as elasti c energy. (C) 2000 Elsevier Science B.V. All rights reserved.