Influence of lubricants on viscoelastic parameters of compaction process

Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department Pharmaceutical technology Candidate Mgr. Petra Svačinová Supervisor Prof. PharmDr. Miloslava Rabišková, CSc. Title of Doctoral Thesis Influence of lubricants on viscoelastic parameters of compaction process This thesis deals with an evaluation of lubricant's influence on viscoelastic parameters of compaction process. The force-displacement record and stress relaxation test were used for this evaluation. This study evaluates the viscoelastic parameters on three fillers intended for direct compression, i.e. microcrystalline cellulose Avicel PH-200, lactose Lactochem Fine Crystals and calcium hydrogen phosphate dihydrate Emcompress. Magnesium stearate and modified colloidal silica Syloid were used as lubricants at concentrations of 0.5 % and 1 %. Particle size and shape and specific surface area were determined for all used excipients. Flow properties were studied for individual fillers and also for their mixtures with lubricants. Subsequently, tablets were compressed from fillers and mixtures using force-displacement record and stress relaxation test, and viscoelastic parameters were evaluated. The applied compression forces for both methods were 5 kN, 10 kN and 15 kN. The hardness of tablets was measured. The results show..