Antibiotic-loaded plaster of Paris implants coated with poly lactide-co-glycolide
as a controlled release delivery system for the treatment of bone infections.
Benoit MA, Mousset B, Delloye C, Bouillet R, Gillard J
Louvain Catholic University, Brussels, Belgium.
Plaster of Paris implants containing vancomycin (60 mg/g of carrier)
were prepared in order to be used as local delivery system for the treatment
of bone infections. The regulation of the release rate was performed by
coating the carrier with a polylactide-co-glycolide polymer composed by
10% (w/w) polyglycolic acid and 90% (w/w) racemic poly (D,L-lactic acid).
The release of the antibiotic from the biodegradable matrix was evaluated
in vitro. From this investigation, it is clear that the drug elution depends
on the coating depth. After a burst effect occurring on the first day of
the experiment, therapeutic concentrations were measured during one week
when uncoated implants were used. The coating allowed decrease of the burst
effect and extended efficient release to more than five weeks when the
implants were embedded with six layers (162 microns) of PLA45GA10. This
delivery system was implanted into the femoral condyle of rabbits. It was
shown that the in vivo release was also closely regulated by the coating
depth. In all bone tissues (bone marrow and cortical bone) surrounding
the pellets, the drug concentration exceeded the Minimum Inhibitory Concentration
for the common causative organisms of bone infections (Staphylococcus aureus)
for at least four weeks without inducing serum toxic levels. Due to its
cheapness, facility of use and sterilization, biocompatibility and biodegradability,
plaster of Paris coated with PLA45GA10 polymer giving a controlled release
of vancomycin appears to be a promising sustained release delivery system
of antibiotics for the treatment of bone and joint infections.
PMID: 9498152, UI: 98159587