Continuous administration of dopa decarboxylase inhibitors and compositions for same
Disclosed herein are compositions that include for example the arginine salt of carbidopa, and methods for treating neurological or movement diseases or disorders such as restless leg syndrome, Parkinson's disease, secondary parkinsonism, Huntington's disease, Parkinson's like syndrome, PSP, MSA, ALS, Shy-Drager syndrome and conditions resulting from brain injury including carbon monoxide or manganese intoxication, using substantially continuous administration of carbidopa or salt thereof together with administration of levodopa.
1. A pharmaceutically acceptable liquid composition comprising carbidopa, levodopa, and arginine, wherein the levodopa and the arginine have a molar ratio of about 1:1.5 to about 1:2.5, wherein the composition comprises about 2% by weight carbidopa, and wherein the pH of the liquid composition is about 8.5 to 9.5 at 25° C.
2. The pharmaceutically acceptable liquid composition of claim 1 , wherein the liquid composition is stable at 25° C. for 48 hours or more.
3. The pharmaceutically acceptable liquid composition of claim 1 , further comprising a pharmaceutically acceptable excipient.
4. The pharmaceutically acceptable liquid composition of claim 1 , wherein the liquid composition is a liquid solution further comprising water.
5. The pharmaceutically acceptable liquid composition of claim 1 , further comprising entacapone or tolcapone.
6. A pharmaceutically acceptable liquid composition comprising 1% by weight carbidopa, and further comprising levodopa, and arginine, wherein the levodopa and the arginine have a molar ratio of about 1:1.5 to about 1:2.5, and wherein the pH of the liquid composition is about 8.5 to 9.5 at 25° C.
7. The pharmaceutically acceptable liquid composition of claim 1 , comprising about 3% to 7% by weight levodopa.
8. The pharmaceutically acceptable liquid composition of claim 1 , wherein the composition is stable for 1 week or more at room temperature.