PORE SWELLING IN BEADS MADE OF CELLULOSE FIBERS AND FIBER FRAGMENTS

The swelling of a new pharmaceutical excipient consisting of highly po rous cellulose beads has been studied. Different degrees of swelling w ere produced by absorption of water and cyclohexane, two liquids with different 'swelling capacity'. The pore size in cellulose beads with d ifferent porosities was investigated using the spin echo NMR technique and found to increase due to swelling. The crystallinity of dry and w et cellulose fibres was investigated using C-13 CP/MAS NMR. A basic ap plication of the beads is to use them as well-defined drug carrier par ticles. The beads can be loaded with drugs by a sorption process from water or organic solvents. It was concluded that it is beneficial to l oad the beads using drug solutions containing a cellulose swelling liq uid.