Compositions of a polyorthoester and an organic acid excipient

1. A method for pain management, comprising:

administering to a subject in need a composition comprising a polyorthoester, maleic acid, an aprotic solvent selected from N-methyl-2-pyrrolidone (NMP) and dimethyl sulfoxide (DMSO), and a therapeutically active agent dispersed or solubilized in the composition,

wherein the therapeutically active agent is selected from the group consisting of bupivacaine, levobupivacaine, dibucaine, mepivacaine, procaine, lidocaine, tetracaine, and ropivacaine, and

wherein the maleic acid is present in less than an equimolar amount when compared to the therapeutically active agent, such that the therapeutically active agent is present as a mixed salt-base and the composition is substantially free of crystals of the therapeutically active agent.

2. The method of claim 1 , wherein the therapeutically active agent is solubilized in the composition.

3. The method of claim 1 , wherein the polyorthoester is selected from polyorthoesters represented by Formulas I, II, III or IV:

where:

R is a bond, —(CH 2 ) a —, or —(CH 2 ) b −)—O—(CH 2 ) c —; where a is an integer of 1 to 12, and b and c are independently integers from 1 to 5;

R* is a C 1-4 alkyl;

R o , R′ and R′″ are each independently H or C 1-4 alkyl;

n is an integer of at least 5; and

A is R 1 , R 2 , R 3 , or R 4 , where

R 1 is an α-hydroxy acid containing subunit

 or

where:

p and q are integers that vary from between 1 and 20, where the average number of p or the average sum of p and q is between 1 and 7;

R 5 is hydrogen or C 1-4 alkyl; and

R 6 is selected from the group consisting of

where:

s is an integer of 0 to 30;

t is an integer of 2 to 200; and

R 7 is hydrogen or C 1-4 alkyl;

R 2 is:

R 3 is:

where:

x is an integer ranging from 0 to 200;

y is an integer ranging from 2 to 200;

R 8 is hydrogen or C 1-4 alkyl;

R 9 and R 10 are independently C 1-12 alkylene;

 R 11 is hydrogen or C 1-6 alkyl and R 12 is C 1-6 alkyl;

or R 11 and R 12 together are C 3-10 alkylene; and

R 4 is the residue of a diol containing at least one functional group independently selected from amide, imide, urea, and urethane groups.

4. The method of claim 1 , wherein the polyorthoester is represented by Formula III:

wherein:

R* is a C 1-4 alkyl, n is an integer ranging from 5 to 400, and A in each subunit is R 1 or R 3 ,

wherein:

R 1 is

where p and q are each independently integers that range from between about 1 to 20, each R 5 is independently hydrogen or C 1-4 alkyl; and R 6 is:

where s is an integer from 0 to 10; t is an integer from 2 to 30; and R 7 is hydrogen or C 1-4 alkyl,

R 3 is:

and x is an integer ranging from 1 to 100; y is an integer in a range from 2 to 30; and R 8 is hydrogen or C 1-4 alkyl.

5. The method of claim 1 , wherein said administering comprises instilling the composition to a surgical site.

6. A method of prophylactic treatment of pain to a patient in need thereof, comprising:

locally administering to the patient in need a composition comprising a polyorthoester, maleic acid, an aprotic solvent selected from N-methyl-2-pyrrolidone (NMP) and dimethyl sulfoxide (DMSO), and an amino-amide anesthetic a therapeutically active agent dispersed or solubilized in the composition,

wherein the therapeutically active agent is selected from the group consisting of bupivacaine, levobupivacaine, dibucaine, mepivacaine, procaine, lidocaine, tetracaine, and ropivacaine, and

wherein the maleic acid is present in less than an equimolar amount when compared to the therapeutically active agent amino-amide anesthetic, such that the therapeutically active agent is present as a mixed salt-base and the composition is substantially free of crystals of the therapeutically active agent.

7. The method of claim 6 , wherein said locally administering is dispensing from a needle.

8. A method for managing or treating post-operative pain, comprising:

administering to a subject in need a composition comprising a polyorthoester, maleic acid, an aprotic solvent selected from N-methyl-2-pyrrolidone (NMP) and dimethyl sulfoxide (DMSO), and an amino-amide anesthetic a therapeutically active agent dispersed or solubilized in the composition,

wherein the therapeutically active agent is selected from the group consisting of bupivacaine, levobupivacaine, dibucaine, mepivacaine, procaine, lidocaine, tetracaine, and ropivacaine, and

wherein the maleic acid is present in less than an equimolar amount when compared to the therapeutically active agent amino-amide anesthetic, such that the therapeutically active agent is present as a mixed salt-base and the composition is substantially free of crystals of the therapeutically active agent.

9. A method for reducing or preventing post-operative pain, comprising:

administering to a subject in need a composition comprising a polyorthoester, maleic acid, an aprotic solvent selected from N-methyl-2-pyrrolidone (NMP) and dimethyl sulfoxide (DMSO), and a therapeutically active agent dispersed or solubilized in the composition,

wherein the therapeutically active agent is selected from the group consisting of bupivacaine, levobupivacaine, dibucaine, mepivacaine, procaine, lidocaine, tetracaine, and ropivacaine, and

wherein the maleic acid is present in less than an equimolar amount when compared to the therapeutically active agent, such that the therapeutically active agent is present as a mixed salt-base and the composition is substantially free of crystals of the therapeutically active agent.