title: Gentamicin encapsulation in PLA/PLGA microspheres in view of treating Brucella infections.
abstract: In view of treating intracellular Brucella infections, microspheres made of poly(lactide) (PLA) and poly(lactide-co-glycolide) (PLGA) were developed as delivery system for the cationic and highly hydrophilic antibiotic gentamicin sulphate. Drug microencapsulation by spray drying yielded microspheres with regular morphology, an average particle size of approximately 3 micrometer and encapsulation efficiencies of up to 45%. Different copolymers of similar molecular weights gave varying encapsulation efficiencies and particle size distributions. The encapsulation efficiency generally increased with polymer hydrophilicity, except for the hydrophilic copolymer PLGA50:50H carrying carboxylic end groups. Encapsulation also depended on the pH value of the aqueous drug solution to be encapsulated. Moreover, increasing nominal gentamicin sulphate loading yielded lower efficiencies. For comparison, some formulations were also prepared by a (W(1)/O)W(2)-solvent evaporation method, which yielded lower encapsulation efficiencies, in the order of 13%. Finally, drug bioactivity was found to remain intact after microencapsulation, MS storage and MS incubation in aqueous medium. The results suggest that PLA/PLGA microspheres prepared by spray drying may be an appropriate delivery system for gentamicin sulphate to be used in the treatment of intracellular Brucella infections.
authors.affiliation: Department of Microbiology, University of Navarra, Pamplona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Prior
authors.forename: C
authors.initials: C
authors.lastname: Gamazo
authors.forename: J M
authors.initials: JM
authors.lastname: Irache
authors.forename: H P
authors.initials: HP
authors.lastname: Merkle
authors.forename: B
authors.initials: B
authors.lastname: Gander
mesh_terms: D001672:Biocompatible Materials / Q000008:administration & dosage / Q000737:chemistry*; D002006:Brucellosis / Q000188:drug therapy; D004339:Drug Compounding; D005839:Gentamicins / Q000008:administration & dosage* / Q000737:chemistry* / Q000494:pharmacology; D019344:Lactic Acid / Q000008:administration & dosage / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D008863:Microspheres; D008970:Molecular Weight; D010316:Particle Size; D011091:Polyesters / Q000008:administration & dosage / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000008:administration & dosage / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000008:administration & dosage / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D001672:Biocompatible Materials; D005839:Gentamicins; D011091:Polyesters; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide)