INVESTIGATIONS OF TABLETS, PREPARED FROM PELLETS PRODUCED BY EXTRUSION AND SPHERONISATION .1. THE APPLICATION OF CANONICAL-ANALYSIS TO CORRELATE THE PROPERTIES OF THE TABLETS TO THE FACTORS STUDIED IN COMBINATION WITH PRINCIPAL COMPONENT ANALYSIS TO SELECT THE MOST RELEVANT FACTORS

Three different types of pellets prepared by extrusion and spheronisat ion were mixed and tabletted by a mechanical press and by a tabletting machine. The objective was to prepare tablets of drug containing pell ets which would disintegrate into the pellets from which they were mad e on adding to fluid. Several factors involved in the production of th e tablets were analysed by canonical analysis, which identified relati onships between the drug loading in the pellets, the proportion of pel lets without the drug, the compression pressure used to prepare the ta blets, the size of the pellets, the diameter of the die, the concavity of the punch and the density, the porosity, the crushing force to bre ak the tablets, the tensile strength, the friability, the disintegrati on time of the tablets and the mean dissolution time of the drug. On o ne hand, the results have shown that the glyceryl monostearate within the pellets inter-acted with the barium sulphate pellets regarding the disintegration times of the tablets. The glyceryl monostearate was im portant as a lubricant, whereas the barium sulphate was important for the disintegration of the tablets. The pressure applied and the size o f the pellets were not major factors to be considered. However, the sh ape of the tip of the punch and the diameter of the punches were very important for the properties of the tablets. By combining the Principa l Component Analysis with the Canonical Analysis, it was possible to s elect the variables which had a greater effect on the properties of th e tablets. (C) 1997 Elsevier Science B.V.