Development and characterization of rosin-based polymer and its application as a cream base

The literature contains many references to the wide range of uses of rosin-based polymers, but little has appeared in the area of rosin-based polymers used as cream bases. Various rosin polymers based on glycerol, sorbitol, and pentaerythritol were prepared and screened for efficacy as cream bases. Among these polymers, polymer 2 (glycerol-based) is reported in the present study as it produced creams with a better stability and release profile as compared to other creams. The creams were formulated employing polymer 2 (P2) and Tween 60 as surfactants. The stability of the prepared creams, as well as the diclofenac diethylammonium release pattern, was investigated using particle size analysis, conductivity, relative dielectric constant, spreadability, and irritation potential measurement, and was compared with that of creams containing Tween 60 (RT) prepared in the laboratory. The release of the drug, diclofenac diethylammonium, was measured after eight hours and compared with a standard cream (RT) and a marketed cream (RM).