Compositions of a polyorthoester and an organic acid excipient
Delivery systems and compositions comprised of a biodegradable polyorthoester polymer, an organic acid excipient, and a basic drug are described, along with related methods.
1. 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 an amino-amide anesthetic selected from the group consisting of bupivacaine, levobupivacaine, dibucaine, mepivacaine, procaine, lidocaine, tetracaine, and ropivacaine, and
maleic acid is present in less than an equimolar amount when compared to the therapeutically active agent, such that the therapeutic agent is present as a mixed salt-base and the composition is substantially free of crystals of the therapeutically active agent.
2. The composition of claim 1 , wherein the therapeutically active agent is bupivacaine or ropivacaine.
3. The composition of claim 1 , wherein the therapeutically active agent is added to the composition in its free base form.
4. The composition 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, or from 1 to 10, 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
where:
p and q are integers that vary from between about 1 and 20, or between about 1 and 15, or between about 1 and 10, where the average number of p or the average of the sum of p and q (i.e., p+q) is between about 1 and 7 when R 1 is present in the poly(orthoester) polymer;
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 19 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.
5. The composition of claim 4 , 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.
6. A semi-solid composition of claim 1 .
7. A composition of claim 1 , wherein the therapeutically active agent is solubilized in the composition.