Drug eluting stent coating with extended duration of drug release

摘要

A stent having a drug eluting formulation has three components: 1) Anti-neointimal hyperplasia or anti-restenosis agent 2) Main polymer 3) Additive polymer The anti-neointimal hyperplasia or anti-restenosis agent includes, but not limited to, Paclitaxel, Taxol, Rapamycin, Tacrolimus, Actinomycin D, Methotrexate, Doxorubicin, cyclophosphamide, and 5-fluorouracil, 6-mercapatopurine, 6-thioguanine, cytoxan, cyclosporine, cytarabinoside, cis-platin, chlorambucil, busulfan, and any other drug that can inhibit cell proliferation, and combinations thereof. The main polymer includes, but not limited to, polystyrene, parylene and polyurethane. The additive polymer includes, but not limited to, polyethylene glycol capped with diisocyanate moiety (NCO-PEG). TABLE Ratio between three components without solvent % Component formulation Agent 1-10% Main polymer 80-98% Additive 1-19% polymer 9.0 g of parylene, 0.6 g of tacrolimus, 0.4 g of NCO-PEG and 0.01 g of triethylene amine were dissolved in 90 g of tetrahydrofuran. The resulting mixture was heated at 40° C. for 30 minutes and cooled to room temperature. To the solution was added 0.1 g of pH 8.0 aqueous solution and mixed thoroughly. The resulting solution is applied to bare metal stents for coating.