Drug loaded polymeric material and method of manufacture

A polymeric material containing a therapeutic drug for application to an intravascular stent for carrying and delivering said therapeutic drug within a blood vessel in which said intravascular stent is placed, comprising:

• a polymeric material having a thermal processing temperature no greater than about 100.degree. C;
• particles of a therapeutic drug incorporated in said polymeric material;
• and
• a porosigen uniformly dispersed in said polymeric material, said porosigen being selected from the group consisting of sodium chloride, lactose, sodium heparin, polyethylene glycol, copolymers of polyethylene oxide and polypropylene oxide, and mixtures thereof.

A method of incorporating a therapeutically effective amount of a therapeutic drug into a polymeric material for application to an intravascular stent, the method comprising the steps of:

• forming solid particles of a therapeutic drug to have a maximum cross-sectional dimension of about 10 microns;
• uniformly dispersing said solid particles of said therapeutic drug in said polymeric material such that said particles of said therapeutic drug form up to about 70% by weight of the total weight of the therapeutic drug and the polymeric material;
• uniformly dispersing a porosigen in said polymeric material together with said therapeutic drug, said porosigen being selected from the group consisting of sodium chloride, lactose, sodium heparin, polyethylene glycol, copolymers of polyethylene oxide and polypropylene oxide, and mixtures thereof;
• and
• applying a rate-controlling membrane over said polymeric material to control the release rate of said therapeutic drug from said polymeric material, said rate controlling membrane being formed of a polymeric material selected from the group consisting of polycaprolactone, poly(ethylene-co-vinyl acetate), poly(vinylacetate), silicone gum rubber, poly-DL-lactic acid (DL-PLA), poly-L-lactic acid (L-PLA), polyorthoesters, polyiminocarbonates, aliphatic polycarbonat polyphosphazenes, and mixtures thereof, said rate controlling membrane polymeric material containing a uniform dispersion of said porosigen.

An apparatus containing a therapeutic drug for application to an intravascular stent for carrying and delivering said therapeutic drug within a blood vessel in which said intravascular stent is placed, comprising:

• a polymeric material having a thermal processing temperature no greater than about 100.degree. C;
• particles of a therapeutic drug incorporated in said polymeric material;
• a porosigen uniformly dispersed in said polymeric material, said porosigen being selected from the group consisting of sodium chloride, lactose, sodium heparin, polyethylene glycol, copolymers of polyethylene oxide and polypropylene oxide, and mixtures thereof;
• and
• a rate-controlling membrane disposed over said polymeric material to control a rate of release of said therapeutic drug from said polymeric material, said rate controlling membrane being formed of a polymeric material selected from the group consisting of polycaprolactone, poly(ethylene-co-vinyl acetate), poly(vinyl acetate), silicone gum rubber, poly-DL-lactic acid (DL-PLA), poly-L-lactic acid (L-PLA), polyorthoesters, polyiminocarbonates, aliphatic polycarbonates, polyphosphazenes, and mixtures thereof, said rate controlling membrane polymeric material containing a uniform dispersion of said porosigen.