SOLVENT-FREE FILM COATING USING A NOVEL PHOTOCURABLE POLYMER

Commercially available film coating polymers are applied with aqueous or organic solvent that must be removed from the coating. In contrast, the results herein presented demonstrate the feasibility of coating without solvent, A liquid silicone-based polymer formulation which can be crosslinked upon ultraviolet irradiation was applied to non-pareil beads to form a relatively impermeable coating. Irradiation exposure and filler content were varied, Bead aggregation and film coating integrity were determined, Film integrity was assessed by marker dye which leaked through defects in the impermeable film coating. Scanning electron micrographs showed smooth continuous coatings with no striations within or between layers of coating. Bead aggregation was reduced by the presence of filler and by an increase in irradiation exposure. Coating integrity increased with an increase in the number of layers of coating. These preliminary results demonstrate the feasibility of coating pharmaceutical cores using a solvent-free photocurable polymer.