[Development of minocycline containing polycaprolactone film as a local drug delivery]

Local drug delivery by using biocompatible polymers has been developed in the treatment of periodontitis for many years. The purpose of this study was to examine the release kinetics of minocycline from monolithic film prepared from polycaprolactone and polyethylene glycol and to examine the antimicrobial activity in vitro. Polycaprolactone (Mwt 60,000), polyethylene glycol and minocyline was dissolved by chloroform, which was vigorously stirred for 24 hours and it was dried in vacuum chamber. The thickness of cast films containing 20%, 30% and 40% minocycline was 200 +/- 10 microns. Release rate of minocycline from the film was measured by means of a UV spectrophotometer. In vitro releasing test, each film showed a large burst effect within first two and three hours and a steady state release kinetic at the rate of 4-8 micrograms/cm/hour for 7 days. In antimicrobial test, each sample (one fourth inch in diameter) sunk in the broth that had been innoculated with periodontopathic bacteria showed growth inhibitory activity after 48 hr anaerobic incubation. In cytotoxicity test, there was no significant cytotoxic effect in casting film to human gingival fibroblast. This study showed that, by embedding minocycline in polycaprolactone, it is feasible to obtain substained release of the drug within the periodontal pocket for seven days and should be useful tool for elimination of pathogenic microflora from periodontal pocket or reducing inflammation in periodontal disease.