| abstract |
THE CRUDE HIGH MOLECULAR WEIGHT POLYGLYCOLIC ACID REQUIRED FOR USE AS AN ABSORBABLE SURGICAL SUTURE SOMETIMES CONTAINS SUBSTANTIAL AMOUNTS OF GLYCOLIDE AND OTHER IMPURITIES. IT HAS BEEN DISCOVERED THAT THE PRESENCE OF SUCH IMPURITIES SIGNIFICANTLY INTERFERES WITH THE EXTRUSION AND STRETCHING CHARACTERISTICS OF POLYGLYCOLIC ACID FILAMENTS AND ITS SATISFACTORY RATE OF ABSORPTION IN LIVING TISSUE. A NOVEL KIND OF POLYGLYCOLIC ACID IS PROVIDED WHICH IS SUBSTANTIALLY FREE FROM SUCH IMPURITIES CONSEQUENTLY HAVING SUITABLE EXTRUSION AND STRETCH PROPERTIES AS WELL AS ACCEPTABLE IN-VIVO STRENGTH RETENTION. THE NOVEL POLYGLYCOLIC ACID IS PREPARED BY CONTACTING PARTICLES OF IMPURITY LADEN POLYGLYCOLIC ACID WITH A FLOWING STREAM OF SUBSTANTIALLY DRY, OXYGEN FREE, INERT GAS UNDER CONTROLLED PROCESS CONDITIONS WHEREBY THE IMPURITIES ARE VAPORIZED INTO THE GAS STREAM TO EFFECT THEIR REMOVAL FROM THE ENVIRONMENT OF THE POLYGLYCOLIC ACID. |