Dynamic model for impact velocity in friability testing : T.Takahashi, P.D.Funkerbusch. (University of Rochester, USA.)

Abstract

Tablets prepared from three different types of pellets were produced either in a mechanical press or in a tabletting machine. The experiments were carried out according to a centre of gravity design. The properties of the tablets produced were predicted from the models based on linear equations with the variables selected by canonical analysis and principal component analysis. The results showed that the variables to be used in the equations of the models for the two machines had to be different, proving the differences in the compaction mechanisms involved. For the Manesty machine, five variables reflected the properties of the tablets produced, whereas for the Instron machine seven variables had to be considered. From the regression it was possible to select the dependent variables (properties of the tablets) that provide a better reflection of the independent variables (formulation and processing factors). Properties such as the value of ‘R’ (ratio between the lower to the upper compression pressures), the density of the tablets, the tensile strength of the tablets, the disintegration time of the tablets, and the mean dissolution time of the model drug (indomethacin) seemed to be well defined by the model. On the other hand, the porosity of the tablets, the force required to crush the tablets, and the friability were not well reflected by the model. Predictions of the changes in the dependent variables when the independent variables were increased by 20% are also presented in the form of star diagrams.