Medical devices having bioerodable layers for the release of therapeutic agents

Abstract

According to an aspect of the present invention, medical devices are provided which comprise: (a) a substrate and (b) bioerodable polymeric layer over the substrate that contains (i) one or more biodegradable polymers (ii) one or more therapeutic agents, and (iii) one or more plasticizers.

1 . A medical device comprising:
 a substrate; and   a bioerodable polymeric layer disposed over the substrate, the bioerodable polymeric layer including poly(lactic acid) or poly(lactic acid-co-glycolic acid) and a plasticizer selected from glycolic acid, an oligomer comprising glycolic acid, and combinations thereof.   
     
     
         2 . The medical device of  claim 1 , wherein the substrate comprises a stent. 
     
     
         3 . The medical device of  claim 1 , wherein the bioerodable polymeric layer further comprises a therapeutic agent. 
     
     
         4 . The medical device of  claim 3 , wherein the therapeutic agent is selected from antiproliferative agents, anti-thrombotic agents, anti-angiogenic agents, anti-restenotic agents, anti-inflammatory agents, anti-migratory agents, agents affecting extracellular matrix production and organization, antineoplastic agents, anti-mitotic agents, anesthetic agents, anti-coagulants, vascular cell growth promoters, vascular cell growth inhibitors, cholesterol-lowering agents, vasodilating agents, agents that interfere with endogenous vasoactive mechanisms, and combinations thereof. 
     
     
         5 . The medical device of  claim 1 , wherein the plasticizer comprises glycolic acid. 
     
     
         6 . The medical device of  claim 1 , wherein the plasticizer comprises an oligomer comprising glycolic acid. 
     
     
         7 . The medical device of  claim 1 , wherein the plasticizer comprises a combination of glycolic acid and an oligomer comprising glycolic acid. 
     
     
         8 . The medical device of  claim 1 , wherein the bioerodable polymeric layer is disposed over a portion of the substrate. 
     
     
         9 . The medical device of  claim 1 , wherein the bioerodable polymeric layer is disposed over all of the substrate. 
     
     
         10 . A stent comprising:
 a substrate; and   a bioerodable polymeric layer disposed over the substrate, the bioerodable polymeric layer including poly(lactic acid) or poly(lactic acid-co-glycolic acid) and a plasticizer selected from glycolic acid, an oligomer comprising glycolic acid, and combinations thereof.   
     
     
         11 . The stent of  claim 10 , wherein the stent has an abluminal surface and a luminal surface, and the biodegradable polymeric layer is disposed over the abluminal surface, but not the luminal surface. 
     
     
         12 . The stent of  claim 10 , wherein the substrate comprises a metallic substrate. 
     
     
         13 . The stent of  claim 10 , wherein the stent comprises a polymeric substrate. 
     
     
         14 . The stent of  claim 10 , wherein the biodegradable polymeric layer comprises poly(lactic acid-co-glycolic acid), and the poly(lactic acid-co-glycolic acid) comprises 30 to 100 wt % lactic acid and 0 to 70 wt % glycolic acid. 
     
     
         15 . The stent of  claim 10 , wherein the biodegradable polymeric layer has a number average molecular weight of 10,000 or more. 
     
     
         16 . The stent of  claim 10 , wherein the biodegradable polymeric layer has a number average molecular weight of 25,000 or more. 
     
     
         17 . A stent comprising:
 a substrate; and   a bioerodable polymeric layer disposed over the substrate, the bioerodable polymeric layer including 50 to 99 wt. % of poly(lactic acid) or poly(lactic acid-co-glycolic acid) and 1 to 50 wt. % of glycolic acid and/or an oligomer comprising glycolic acid.   
     
     
         18 . The stent of  claim 17 , wherein the substrate comprises a metallic substrate. 
     
     
         19 . The stent of  claim 17 , wherein the stent comprises a polymeric substrate. 
     
     
         20 . The stent of  claim 17 , wherein the stent has an abluminal surface and a luminal surface, and the biodegradable polymeric layer is disposed over the abluminal surface, but not the luminal surface.