Phosphate based biodegradable polymers

A process for preparing a biodegradable polymer comprising the recurring monomeric units of formula I:

• wherein:
• R is hydrogen, optionally substituted C2-12-alkenyl, optionally substituted heteroalkyl, optionally substituted C2-12-alkynyl, or optionally substituted alkyl;
• R1, R2, R3, R4, R5 and R6 are each independently chosen from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted C2-12-alkenyl, optionally substituted C2-12-alkynyl, and optionally substituted alkoxy;
• x is 2, 3, or 4;
• n and m are non-negative integers;
• n+m is about 5 to about 2000;
• and,
• m:n is between about 1:100 to about 100:1;
• wherein the process comprising the steps of:
• contacting at least one glycolide derivative and at least one cyclic phosphate;
• and
• polymerizing the glycolide derivative and the cyclic phosphate under conditions conducive to preparing the biodegradable polymer.

A process for preparing a biodegradable polymer comprising the recurring monomeric units of formula III:

• wherein:
• R is hydrogen, optionally substituted C2-12-alkenyl, optionally substituted heteroalkyl, optionally substituted C2-12-alkynyl, or optionally substituted alkyl;
• R1 and R2 are each independently chosen at each occurrence from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted C2-12-alkenyl, optionally substituted C2-12-alkynyl, and optionally substituted alkoxy;
• L is chosen from the group consisting of optionally substituted C2-12-alkyl, optionally substituted heteroalkyl, optionally substituted C2-20-alkenyl, optionally substituted C2-20-alkynyl, or —(CH2)a—{O—(CH2)a}b—, wherein each a is 1-6 and b is 1-500;
• n and m are non-negative integers;
• n+m is about 5 to about 2000;
• x is 2, 3 or 4;
• and
• M is independently chosen at each occurrence of M from the group consisting of H, Na, Li, and K;
• the process comprising the steps of:
• contacting at least one cyclic phosphate with an initiator compound, HO—L—OH;
• polymerizing the cyclic phosphate with the initiator compound under conditions conducive to preparing the biodegradable polymer.

A biodegradable polymer composition comprising:

• (a) at least one biologically active substance;
• and
• (b) a biodegradable polymer comprising at least one repeat unit according to formula A:
• wherein
• R is hydrogen, optionally substituted alkyl, optionally substituted C2-12-alkenyl, optionally substituted heteroalkyl, optionally substituted C2-12-alkynyl, or optionally substituted C5-8-cycloalkyl;
• R1 and R2 are each independently chosen from the group consisting of H, optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted C2-12-alkenyl, optionally substituted C2-12-alkynyl, and optionally substituted alkoxy;
• x is 2, 3, or 4;
• and
• at least one repeat unit selected from the group consisting of alkyl, C2-20-alkenyl, C2-20-alkynyl, optionally substituted heteroalkyl, —O(CR1R2)cC(O)— where c is between about 1 and about 10, —(CH2)a—{O(CH2)a}b— where a is between about 1 and about 7 and b is between about 1 and about 500, aryl, and heteroaryl;
• or
• at least one repeat unit according to formula B:
• wherein
• R3, R4, R5 and R6 are each independently chosen from the group consisting of H, optionally substituted alkyl, optionally substituted C2-12-alkenyl, optionally substituted C2-12-alkynyl, optionally substituted heteroalkyl, and optionally substituted alkoxy.