Abstract

Tablets of aspirin (a moisture degradable drug) have been film coated with two analogous Eudragit RL and RS copolymers designated here as A and B which differ only in their cation content in the ratio 2:1 (A:B). A, is therefore more hydrophilic than B. The tablets were film coated with ethanol solutions of these two polymers. Film coating with either A or B significantly reduced the moisture uptake potentials of the tablets but caused an increase in the disintegration times of the tablets and retarded dissolution rates. The mean disintegration times were 0.5±0.1 min (uncoated tablets), 16±2.5 min (tablets coated with A) and 115±3.6 min (tablets coated with B). The corresponding dissolution rates % h -1 were 28.3 for uncoated, 16.6, coated with A and 14.8, coated with B, respectively. Thus, coating with polymer B considerably impaired the disintegration and dissolution properties of the tablets.