Incorporation of triclosan into polydioxanone monofilaments and evaluation of the corresponding release

Abstract

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 wellestablished 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 Sö rensen's hydrophilic medium was used. Significant differences in the release profiles of a Sö rensen'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 lg/g) sutures dropped to 220.000 and 110.000 after 45 days of exposure to the medium at 37 C, respectively.

Infusion of iodine-based contrast agents into poly(p-dioxanone) as a radiopaque resorbable IVC filter

“…Solvents were selected to optimize the solubility of the iodine-based contrast agents and maximize the loading of these agents into the PPDO. At first, DCM was our preferred solvent to dissolve IBC and TIBA for infusing into PPDO sutures because DCM is less toxic than chloroform and PPDO sutures can swell in DCM [12]. However, IBC and TIBA are almost completely insoluble in 100% DCM.…”

“…PPDO slightly swells in some organic solvents, such as dichloromethane (DCM) and chloroform [12,13]. Thus, low molecular weight compounds that are soluble in organic solvents could be loaded into the polymer by diffusion through exposure to a DCM solution of such a compound.…”

“…Thus, low molecular weight compounds that are soluble in organic solvents could be loaded into the polymer by diffusion through exposure to a DCM solution of such a compound. This approach has previously been studied to incorporate ibuprofen and triclosan into PPDO monofilaments [12,13]. In addition, the kinetics and release of triclosan incorporation into absorbable polymer monofilaments were also evaluated [14,15].…”

“…In addition, the kinetics and release of triclosan incorporation into absorbable polymer monofilaments were also evaluated [14,15]. Promisingly, the filaments with triclosan through exposure to DCM solution did not significantly affect the mechanical properties of the monofilaments [12]. …”

“…Although the percentage of IBC in the PPDO was higher than that of TIBA per elemental analysis, it could be argued that the IBC molecule is smaller and less bulky than the TIBA molecule since the TIBA molecule has two more iodine atoms, and therefore IBC can be more easily infused in PPDO than TIBA can be (Figure 1). However, IBC and TIBA showed lower percentages of loading into PPDO than triclosan does [12]. It may be due to the fact that triclosan dissolves very well in DCM and 100% DCM can swell or open the surface of PPDO for encapsulation better than the 5–10% DMSO-DCM mixture can.…”