Process of Making Bioabsorbable Filaments

Abstract

Methods for making bioabsorbable copolymer filaments are provided herein. The methods include drying the polymer pellets to be extruded, melt extrusion of copolymer components, stretching the filaments in one or more draw steps and permitting the drawn filaments to relax. The copolymer preferably contains units derived from glycolide or glycolic acid and units derived from an alkylene carbonate, such as, for example, trimethylene carbonate.

1 . A process for manufacturing a monofilament suture from a block copolymer comprising from about 50 to about 80 weight percent glycolide, and about 20 to about 50 weight percent trimethylene carbonate, the method comprising: a) extruding the copolymer to provide a monofilament; b) drawing the monofilament through a first oven maintained at a first temperature at a first draw ratio; c) drawing the monofilament through a second oven maintained at a second temperature at a second draw ratio; and d) drawing the monofilament through a third oven maintained at a temperature of about 125° C. to about 165° C. at a draw ratio of about 0.5:1 to about 0.8:1. 
     
     
         2 . The process of  claim 1  wherein the step of extruding the copolymer comprises extruding the copolymer at a temperature from about 170° C. to about 240° C. 
     
     
         3 . The process of  claim 1  wherein the step of extruding the copolymer further comprises quenching the monofilament. 
     
     
         4 . The process of  claim 3  wherein the step of quenching the monofilament comprises utilizing a quench bath at a temperature from about 10° C. to about 80° C. 
     
     
         5 . The process of  claim 1  wherein the step of drawing the monofilament through the first oven maintained at a first temperature at a first draw ratio comprises the first oven maintained at a temperature of about 25° C. to about 40° C. 
     
     
         6 . The process of  claim 1  wherein the step of drawing the monofilament through the first oven maintained at a first temperature at a first draw ratio comprises a first draw ratio of about 2:1 to about 15:1. 
     
     
         7 . The process of  claim 1  wherein the step of drawing the monofilament through the first oven maintained at a first temperature at a first draw ratio comprises a first draw ratio of about 3:1 to about 12:1. 
     
     
         8 . The process of  claim 1  wherein the step of drawing the monofilament through the second oven maintained at a second temperature at a second draw ratio comprises the second oven maintained at a temperature of about 30° C. to about 150° C. 
     
     
         9 . The process of  claim 1  wherein the step of drawing the monofilament through the second oven maintained at a second temperature at a second draw ratio comprises a second draw ratio of about 1.1:1 to about 5:1. 
     
     
         10 . The process of  claim 1  wherein the step of drawing the monofilament through the second oven maintained at a second temperature at a second draw ratio comprises a second draw ratio of about 1.2:1 to about 3:1. 
     
     
         11 . The process of  claim 1  wherein the step of drawing the monofilament through the second oven maintained at a second temperature at a second draw ratio comprises a second draw ratio of about 1.25:1 to about 1.5:1. 
     
     
         12 . The process of  claim 1  wherein the step of drawing the monofilament through the third oven comprises drawing at a draw ratio of about 0.55:1 to about 0.75:1. 
     
     
         13 . The process of  claim 1  wherein the step of drawing the monofilament through the third oven comprises drawing the monofilament through a third oven maintained at a temperature of about 128° C. to about 150° C. 
     
     
         14 . The process of  claim 1  further comprising the step of annealing the monofilament. 
     
     
         15 . The process of  claim 14  wherein the step of annealing the monofilament comprises subjecting the monofilament to temperatures ranging from about 100° C. to about 180° C. 
     
     
         16 . The process of  claim 14  wherein the step of annealing the monofilament further comprises winding a single layer of the monofilament around a large drum off-line. 
     
     
         17 . The process of  claim 14  wherein the step of annealing lasts from about 9 to about 24 hours. 
     
     
         18 . The process of  claim 1  wherein the monofilament suture further comprises at least one medico-surgically useful substance. 
     
     
         19 . The process of  claim 1  wherein the at least one medico-surgically useful substance comprises an antimicrobial agent. 
     
     
         20 . The process of  claim 1  wherein the block copolymer comprises from about 60 to about 70 weight percent glycolide, and about 30 to about 40 weight percent trimethylene carbonate.