Production and Characterization of Plga Nanocapsules Loaded with Doxycycline Hyclate by Using a Supercritical Technology

In this work, poly-lactic-co-glycolic acid (PLGA) nanocapsules loaded with doxycycline hyclate (DOX) were produced by using a supercritical carbon dioxide-based process, called Supercritical Emulsion Extraction (SEE). DOX was used as a model drug, since a prolonged release is needed to avoid frequent administration. Starting from a water-oil-water (w1-o-w2) double emulsion, the organic solvent was removed from the oil phase through supercritical CO2. The resulting nanocapsules showed a unimodal particles distribution, with a mean size of 170 ± 75 nm and an encapsulation efficiency of 66%. Morphological analysis was performed by field emission scanning electron microscope (FE-SEM), showing spherical-shaped nanoparticles. The same loaded nanoparticles were also produced by the conventional method, based on the evaporation of the solvent from the double emulsion. In this case, aggregated nanoparticles with low entrapment efficiency (i.e., 18%) were obtained. In vitro drug release tests performed on PLGA loaded nanocapsules produced by SEE showed a prolonged and controlled release of DOX.