MICROENCAPSULATION OF AN IRON CHELATOR FOR SUSTAINED-RELEASE AND CRYSTAL HABIT MODIFICATION

DMHP (1,2-dimethyl-3-hydroxy-pyrid-4-one) is an orally-active iron che lator that has a short biological half-life and hence a sustained-rele ase formulation is currently being developed. DMHP exists as needle-li ke crystals that cannot be size-characterized accurately for pharmaceu tical manufacturing The current study was undertaken to simultaneously achieve crystal-habit modification and provide sustained-release prop erties using a microencapsulation technique. Eudragit-RS, -RL, -L90 an d Cellulose Acetate Phthalate were used in a phase-separation method t o produce discrete, spheroidal, free flowing microcapsules of DMHP tha t could be sized readily. The obtained microcapsules were evaluated fo r drug content, size distribution, micromeritic properties, and in-vit ro dissolution in gastric followed by intestinal pH environments at 37 degrees C. In-vitro dissolution studies revealed that DMHP release fr om the microcapsules can be retarded for up to 10 h. Changes in polyme r type, polymer content, and processing parameters resulted in drastic changes in the microencapsulation process, and release characteristic s of the microcapsules.