Biodegradable micro- and nanoparticles as long-term delivery vehicles for gentamicin. - Spray Drying

Biodegradable micro- and nanoparticles as long-term delivery vehicles for gentamicin.
2006 Nov
Lecaroz C, Gamazo C, Renedo MJ, Blanco-Prieto MJ.
J Microencapsul.
PubMed
Department of Microbiology.
Micro- and nanoparticles of poly(lactide-co-glycolide) (PLGA) loading gentamicin were prepared by a solvent evaporation method with the aim of obtaining appropriate vectors for systemic administration. Microspheres presented mean diameters below 3 microm and nanoparticles showed homogeneous sizes with a diameter of 320 nm. Drug loading was more efficient in the case of microencapsulation. The more hydrophilic copolymers with carboxyl-end groups yielded higher microparticle loadings, reaching encapsulation efficiencies up to 9.2 microg mg-1 of polymer (502H, 503H or 75:25H). Nanoparticles made of 502H PLGA also achieved an acceptable level of encapsulation (6.2 microg mg-1). Particles prepared by using the solvent evaporation method showed no aggregation after hydration, in contrast to the microparticles prepared by spray-drying which showed fast and high auto-aggregation. In vitro release profiles revealed that 503H microspheres showed the highest burst during the first hour, while the most sustained release was for microparticles of 502H copolymer (40% of gentamicin remained in the formulation after 28 days). In summary, microspheres made of 502H, 503H and 75:25H and nanoparticles of 502H showed the best potential properties for systemic use in the treatment of intra-cellular gentamicin-susceptible pathogens.
PMID: 17123922 [PubMed - in process]