COMPRESSION OF ENTERIC-COATED PELLETS TO DISINTEGRATING TABLETS - UNIFORMITY OF DOSAGE UNITS

Enteric-coated bisacodyl pellets were compressed into tablets using gr anules and powders as filler-binders of different particle size and co hesiveness. The effects on the uniformity of content and mass were inv estigated. The mixtures contained between 10 and 70% mass/mass pellets with a particle size in the range 0.8-1.25 mm. Egermann's equations w ere used to calculate the coefficients of random variation of content. Tablets containing 10% mass/mass pellets showed pronounced variations in mass and content. This was attributed to the large particle size o f the pellets as compared with the tablet size, Mixtures with 30% mass /mass pellets showed good uniformity of mass and of content if additio nal granules were used as excipients. segregation occurred if only fin er excipients were used. With 50-70% mass/mass pellets in a tablet, go od content uniformity was found with all filler-binders used. This can be explained by the formation of a percolating cluster of the pellets , which prevented segregation. With 50% mass/mass, corresponding to 30 % vol./vol., and more pellets in the mixture, the coefficient of varia tion of content agreed well with the values calculated according to Eg ermann's equations. (C) 1998 Elsevier Science S.A. All rights reserved .