In a recent multicenter trial probucol was found to reduce stent restenosis by improving the lumen dimension. The probucol was administered for 2 weeks before, and 4 weeks after, stenting. The release of the drug at the site of a vascular injury, via polymer-coated stents, helps achieve an effective local concentration. The feasibility of a probucol stent coating in reducing in-stent restenosis was assessed.

The probucol loading and in vitro release were assessed using BiodivYsioTM stents, in a 50 mg/mL probucol solution. After being dip-coated with probucol (n=8), or a control (n=8) solution, the stents were implanted in 8 pigs. Angiography and histopathological analyses were performed 28 days later.

The total probucol loading was 52±16 microgram/stent, with no release for up to 72 hours after loading. No pig died until sacrifice. On angiography, the reference and minimum lumen diameters showed no significant differences between the two groups, with similar diameters stenosis (8.7±3.68 vs. 13.3±4.18%, p=0.120). On histomorphometry, the injury scores, vessel, lumen and neointimal areas showed no significant differences between the groups, with similar areas of stenosis (23.1±12.39 vs. 25.2±8.22%, p=0.671). The degrees of re-endothelialization, inflammation and smooth muscle cell proliferation were not significantly different.

Probucol can be loaded onto a polymer-coated stent, and does not release from the stent for up to 72 hours after loading. About 52 microgram probucol per stent does not reduce in-stent restenosis in porcine coronary arteries.