Development and physicochemical characterization of dexamethasone-loaded polymeric nanocapsule suspensions

The influence of drug concentration, oil phase, and surfactants on the characteristics of dexamethasone-loaded nanocapsules was investigated. The best formulations were obtained at dexamethasone concentrations of 0.25 and 0.50 mg.mL-1 (encapsulation efficiency: 80-90%; mean size: 189-253 nm). The type of oil phase influenced only the stability of dexamethasone-loaded nanocapsules. The association of polysorbate 80 and sorbitan monooleate provided a more stable formulation. Sunflower oil and sorbitan sesquioleate used for the first time as oil phase and surfactant for nanocapsules, respectively, have allowed obtaining suspensions with low mean size and narrow size distribution.