TY - JOUR T1 - Differences between eccentric and rotary tablet machines in the evaluation of powder densification behaviour. AU - Palmieri,Giovanni F, AU - Joiris,Etienne, AU - Bonacucina,Giulia, AU - Cespi,Marco, AU - Mercuri,Annalisa, PY - 2004/11/15/received PY - 2005/03/14/revised PY - 2005/04/14/accepted PY - 2005/6/14/pubmed PY - 2005/10/15/medline PY - 2005/6/14/entrez SP - 164 EP - 75 JF - International journal of pharmaceutics JO - Int J Pharm VL - 298 IS - 1 N2 - Differences in the dynamics of powder densification between eccentric and rotary machine were pointed out by compressing at different compression pressures microcrystalline cellulose, lactose monohydrate and dicalcium phosphate dihydrate and recovering the corresponding stress/strain data in both machines equipped to monitor punches displacement and compression forces. Heckel plots were then obtained from these stress/strain data. Curves obtained in the rotary machine possess a narrower zone of linearity for the calculation of P(Y) and D(A). The effect of the different compression mechanism of the rotary machine on the shape of the Heckel plot is more noticeable in a non-deforming material such as dicalcium phosphate. The effect of the longer dwell time of the rotary machine on the porosity reduction occurring after the maximum pressure has been reached, is more noticeable in a ductile material such as microcrystalline cellulose. Heckel parameters obtained in the rotary press are in some cases different from those recovered in the eccentric machine because of the longer dwell time, machine deflection and punch tilting occurring in the rotary machine, although theoretically they could better describe the material densification in a high speed production rotary machine. SN - 0378-5173 UR - https://www.unboundmedicine.com/medline/citation/15951144/Differences_between_eccentric_and_rotary_tablet_machines_in_the_evaluation_of_powder_densification_behaviour_ DB - PRIME DP - Unbound Medicine ER -