Extraction of solvents from drug containing polymer reservoirs
View Patent ↗A process for reducing solvent contents in drug-containing polymeric compositions may be utilized to reduce the solvent content in implantable medical device wherein the compositions are in reservoirs. Specifically, the solvent contents in the drug-containing polymeric compositions are first reduced by one or more conventional drying methods, to a range from about 0.5 weight percent to about 10 weight percent of the total weight of the polymeric composition. Subsequently, the drug-containing polymeric compositions are further treated by a low temperature drying method for further reduction of the solvent content.
1. A method for extracting solvents from a polymeric/therapeutic agent matrix contained within reservoirs of a medical device comprising removing a majority of the solvent utilizing low temperature drying to a level of less than about 5 weight percent without performing a conventional drying method and then exposing the medical device to carbon dioxide at a pressure in the range from about sixty bar to about sixty-five bar at a temperature in the range from about twenty-five to about thirty-six degrees C. for a time period less than twenty five minutes.
2. The method for extracting solvents according to claim 1 , wherein the medical device comprises a stent having a plurality of through-holes.
3. The method for extracting solvents according to claim 1 , wherein the medical device comprises a stent having a plurality of blind holes.
4. The method for extracting solvents according to claim 2 , wherein the stent comprises a metallic material.
5. The method for extracting solvents according to claim 2 , wherein the stent comprises a polymeric material.
6. The method for extracting solvents according to claim 3 , wherein the stem comprises a metallic material.
7. The method for extracting solvents according to claim 3 , wherein the stent comprises a polymeric material.
8. The method for extracting solvents according to claim 1 , wherein the polymeric/therapeutic agent matrix comprises a bioabsorbable polymer and a rapamycin, its analogs or derivatives.
9. The method for extracting solvents according to claim 8 , wherein the polymeric/therapeutic agent matrix comprises poly(lactic-co-glycolic acid) PLGA, and sirolimus.