A medicinal covering material (A) of resorbable polymer is formed from a lactide-trimethylene carbonate- epsilon -caprolactone terpolymer (I). A medicinal covering material (A) of resorbable polymer is formed from a lactide-trimethylene carbonate- epsilon -caprolactone terpolymer (I), comprising not more than 85 wt. % lactide, 5-20 wt. % trimethylene carbonate and 5-20 wt. % epsilon -caprolactone. An Independent claim is included for the production of (A), involving forming (I) by polymerization of the appropriate monomers and shaping (I) into the required form.
