Incorporation of Triclosan into Polydioxanone Monofilaments and Evaluation of the Corresponding Release

摘要

Poly(p-dioxanone) monofilaments were loaded with triclosan, a drug with a well-known antimicrobial effect. Two different procedures were considered: loading by molecular diffusion with a swelling solvent such as dichloromethane and loading by means of a coating based on polycaprolactone or polycaprolactone/magnesium stearate mixtures. Triclosan release was studied in different media by high-performance liquid chromatography. The kinetics of loading by diffusion and the release from both kinds of preparations were evaluated with well-established models. In general, the first stages of the loading process fit with the Higuchi approximation, whereas the final stages fit with the first-order model. The last model could be applied to predict the release behavior. A sustained release over a period that could reach 400 h was attained when ethanol was added to the release medium, whereas equilibrium conditions were reached when Sorensen's hydrophilic medium was used. Significant differences in the release profiles of a Sorensen's/ethanol medium were observed, which depended on the loading methodology. Thus, an 80% release was attained after 36 h for a polycaprolactone-coated sample and after 80-100 h for a sample loaded by diffusion. Degradation studies of the triclosan-loaded samples were also performed because the increase in the hydrophobicity of the samples could hinder the hydrolytic degradation. The weight-average molecular weight of unloaded and loaded (29,075 mu g/g) sutures dropped to 220.000 and 110.000 after 45 days of exposure to the medium at 37 degrees C, respectively.