Biodegradable terephthalate polyester-poly (phosphonate) compositions, articles, and methods of using the same

A biodegradable terephthalate copolymer composition comprising:

• (a) at least one biologically active substance and
• (b) a copolymer having the recurring monomeric units shown in formula I:
• ##STR20## wherein R is a divalent organic moiety;
• R' is an aliphatic, aromatic or heterocyclic residue;
• x is.gtoreq.1;
• and
• n is 3-7,500,
• where the biodegradable polymer is sufficiently pure to be biocompatible and is capable of forming biocompatible residues upon biodegradation.

A method for the controlled release of a biologically active substance comprising the steps of:

• (a) combining the biologically active substance with a biodegradable terephthalate copolymer having the recurring monomeric units shown in formula I:
• ##STR22## wherein R is a divalent organic moiety;
• R' is an aliphatic, aromatic or heterocyclic residue;
• x is.gtoreq.1;
• and
• n is 3-7,500,
• where the biodegradable polymer is sufficiently pure to be biocompatible and is capable of forming biocompatible residues upon biodegradation, to form an admixture;
• (b) forming said admixture into a shaped, solid article;
• and
• (c) implanting or injecting said solid article in vivo at a preselected site in an animal, such that the solid implanted or injected matrix is in at least partial contact with a bio-logical fluid.