Microencapsulation of gentamicin in biodegradable PLA and/or PLA/PEG copolymer.
Biodegradable carriers containing gentamicin for local treatment of bone infection were developed. This paper describes the preparation and in vitro evaluation of these biodegradable implants. Poly-L-lactic acid (PLA) and poly-L-lactic acid:polyethylene glycol (PLA/PEG) disk implants containing gentamicin sulphate were obtained by compression of microspheres prepared by a double emulsion process. The mean particle size distribution of the microspheres, based on volume, ranged from 95-270 microm. The gentamicin sulphate loading of the microspheres, after a methylene chloride-water extraction procedure, exceeded 90% of the theoretical value. In vitro dissolution studies on the microspheres and implants with drug loadings 10-40% w/w indicated that the rate of drug release from both PLA and PLA/PEG implants increased, with an increase in drug loading. The release of gentamicin from microspheres was dependent on the properties of PLA and/or PLA/PEG. The PLA/PEG copolymer was more hydrophilic than the PLA homopolymer, and with a smaller pH change in the microenvironment with polymer being degraded. In comparison, the PLA/PEG implant released antibiotic faster and had a larger inhibitory zone based on the Bauer-Kirby experiments used to test the inhibitory activity of antimicrobial devices. Experimental results showed that the biodegradable PLA/PEG gentamicin delivery system had a potential for prophylaxis of post-operative infection.
Huang
Y Y
YY
Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei. yyhuang@ha.mc.ntu.edu.tw
Chung
T W
TW
D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D001673:Biodegradation, Environmental; D002214:Capsules; D004337:Drug Carriers; D004339:Drug Compounding / Q000379:methods; D005839:Gentamicins / Q000008:administration & dosage*; D006801:Humans; D066298:In Vitro Techniques; D007773:Lactates; D019344:Lactic Acid; D008855:Microscopy, Electron, Scanning; D010019:Osteomyelitis / Q000188:drug therapy; D011091:Polyesters; D011092:Polyethylene Glycols; D011108:Polymers
D000900:Anti-Bacterial Agents; D002214:Capsules; D004337:Drug Carriers; D005839:Gentamicins; D007773:Lactates; D011091:Polyesters; D011108:Polymers; C088513:poly(lactic acid-ethylene glycol); D019344:Lactic Acid; D011092:Polyethylene Glycols; C033616:poly(lactide)