Evaluation of high- and low-energy methods for the entrapment of florfenicol into poly (lactide-co-glycolide) nanoparticles

LUCIANO MENGATTO; KARP FEDERICO; D.A. ESTENOZ; DR. JULIO A. LUNA

Congreso; TMNC; 2016

Lab. Qca. Fina.- INTEC - UNL - CONICET

Poly(lactide-co-glycolide) (PLGA) is a biodegradable and biocompatible synthetic aliphatic polyester with a well known use in pharmaceutical applications that are under development or already approved by FDA. Florfenicol is a broad-spectrum antibiotic indicated in the treatment of infectious diseases in cattle and pigs. This work is based on the production and characterization of PLGA nanoparticles for the entrapment of florfenicol at different initial concentrations (between 6% and 82% w/w of PLGA) obtained by two different techniques. Confined Impinging Jets Reactors (CIJR) are special devices with a cylindrical chamber where two inlet opposite streams of organic and aqueous phases are discharged and mixed leading to solvent-displacement, also called nanoprecipitation. The hydrophobic PLGA and the drug were dissolved in acetone and mixed into the water phase. The water-miscible solvent immediately diffused leading to polymer precipitation and nanoparticle formation. On the other hand, emulsion-solvent evaporation method was based on the emulsification of PLGA/ethyl acetate phase (containing the drug) into PVA 2%/water phase. Mixing energy was provided by a sonicator. Solvent removal by evaporation resulted in polymer precipitation and nanoparticles formation. With respect to mean size, CIJR resulted in a highly reproducible method with smaller PLGA nanoparticles production, with mean size of 95nm against 200-270nm obtained from sonication. No change in mean size of particles was observed after modifing initial drug concentration for CIJR. The behavior of sonicator particles with this respect was fluctuating. CIJR showed to be less efficient regarding to florfenicol entrapment. While emulsion-solvent evaporation loaded near 50% of initial drug concentration, nanoprecipitation method wasted more than 80% of florfenicol. The higher drug loading was near 13% (w/wPLGA) thanks to sonicator based technique. As disadvantage, this method requires higher mixing energy and the use of surfactants compared with CIJR. Recent research works studied the entrapment or adsorption of florfenicol within nanoparticles made of different materials, but no information was found related to PLGA nanoparticles.