Evaluation of new rosin derivatives for pharmaceutical coating.

Rosin and Rosin-based polymers have diversified drug delivery applications achieving sustained/controlled release profiles. In this manuscript, two new Rosin derivatives were synthesized and evaluated for physicochemical properties, molecular weight, polydispersity and glass transition temperature. Plasticizer-free films prepared by solvent evaporation were tested for surface morphology, water vapour transmission and mechanical properties (tensile strength, percent elongation and modulus of elasticity). The films showed low tensile strength and high percent elongation values achieving smooth and uniform surface. The derivatives were further characterized for film coating by evaluating the release of a model drug (diclofenac sodium) from pellets coated with the rosin derivatives as retarding membrane. Drug release was sustained up to 10 h due to 10% (w/w) coat built up with the new rosin derivatives. Increase in coat-built-up further facilitated sustained release from coated forms. Film coating could be achieved without agglomeration of the pellets within a reasonable operating time. The present study proposes novel film forming materials with potential use in sustained drug delivery.