FORMULATION FOR THE TREATMENT OF PAIN
Formulations and methods are provided for the treatment of pain, and neuropathic pain in particular. The formulations are eutectic mixtures of a capsaicinoid and a local anesthetic agent and/or an anti-pruritic agent.
1 . A substantially nonaqueous therapeutic formulation comprising a binary eutectic mixture of:
(a) a capsaicinoid having the structure of formula (I)
wherein R 1 is hydrogen, hydroxyl or methoxy, R 2 is hydroxyl or C 2 -C 6 alkoxycarbonyl, X is selected from
and R is selected from C 5 -C 11 alkyl, C 5 -C 11 alkenyl, C 11 -C 23 cis-alkenyl, C 11 -C 23 alkynyl, and C 11 -C 23 alkadienyl, provided that the capsaicinoid is other than capsaicin; and
(b) a second active agent effective to decrease at least one side effect associated with capsaicin monotherapy, said second agent existing as a solid at 25° C.
2 . The formulation of claim 1 , wherein the capsaicinoid is selected from resiniferatoxin, N-vanillyl-alkadienamides, N-vanillyl-alkanedienyls, N-vanillyl-monounsaturated alkenamides, N-vanillylsulfonamides, and hydroxyphenylacetamides.
3 . The formulation of claim 2 , wherein the capsaicinoid is an N-vanillyl monounsaturated alkenamide.
4 . (canceled)
5 . The formulation of claim 1 , wherein the second active agent is a local anesthetic agent.
6 . The formulation of claim 5 , wherein the local anesthetic agent is selected from amylocaine, articaine, benzocaine, bupivacaine, butacaine, 2-chloroprocaine, cinchocaine, dexivacaine, diamocaine, dibucaine, etidocaine, ketocaine, lidocaine, mepivacaine, oxybuprocaine, parethoxycaine, prilocaine, procaine, propanocaine, proparacaine, propoxycaine, pyrrocaine, risocaine, rodocaine, ropivacaine, tetracaine, and combinations thereof.
7 . The formulation of claim 6 , wherein the local anesthetic agent is lidocaine.
8 . The formulation of claim 6 , wherein the local anesthetic agent is tetracaine.
9 . The formulation of claim 5 , wherein the capsaicinoid represents about 10 wt. % to about 70 wt. % of the formulation.
10 . The formulation of claim 9 , wherein the capsaicinoid represents about 40 wt. % to about 70 wt. % of the formulation.
11 . The formulation of claim 5 , wherein the second active agent is an anti-pruritic agent.
12 . The formulation of claim 11 , wherein the anti-pruritic agent is selected from menthol, camphor, phenol, and combinations thereof.
13 . The formulation of claim 12 , wherein the capsaicinoid represents 10 wt. % to about 70 wt. % of the formulation.
14 . The formulation of claim 13 , wherein the capsaicinoid represents about 40 wt. % to about 70 wt. % of the formulation.
15 - 24 . (canceled)
25 . The formulation of claim 12 , wherein the capsaicinoid represents 10 wt. % to about 50 wt. % of the formulation.
26 . (canceled)
27 . The method of claim 12 , wherein the eutectic mixture is administered by injection.
28 . A method for treating a patient suffering from pain, comprising administering to the patient a therapeutically effective amount of the formulation of claim 1 .
29 . The method of claim 28 , wherein the formulation is administered topically.
30 . The method of claim 29 , wherein the pain is caused by inflammation of joints, tendons, nerves, or muscle.
31 - 33 . (canceled)
34 . The method of claim 28 , wherein the pain is caused by cancer.
35 . The method of claim 28 , wherein the pain is neuropathic pain.
36 - 39 . (canceled)