1. Arginine salt of an active agent selected from carbidopa and levodopa. 2. A pharmaceutically acceptable liquid or gel composition comprising the arginine salt of claim 1, possibly containing a pharmaceutically acceptable excipient. A pharmaceutically acceptable liquid composition according to claim 2, characterized in that it contains a carbidopa arginine salt. A pharmaceutically acceptable liquid composition comprising (a) arginine； and (b) an active agent selected from carbidopa, levodopa, or a combination of these agents. A pharmaceutically acceptable liquid composition according to claim 4, comprising arginine and carbidopa, said composition comprising preferably at least about 1 wt.% Or at least about 4 wt.% Carbidopa. The pharmaceutically acceptable liquid composition according to claim 5, wherein the carbidopa and arginine are contained in a molar ratio selected from a ratio of from about 1: 0.5 to about 1: 2.5, or from about 1: 1 to about 1: 1, 2.7. The pharmaceutically acceptable liquid composition according to claim 4, containing at least about 4 wt.% Levodopa. The pharmaceutically acceptable liquid composition according to claim 7, characterized in that levodopa and arginine are contained in a molar ratio of from about 1: 1.5 to about 1: 2.5.9. A pharmaceutically acceptable liquid composition according to any one of claims 4 to 8, further comprising a pharmaceutically acceptable excipient, preferably selected from N-methylpyrrolidone, polyvinylpyrrolidone, propylene glycol, antioxidants, or a combination thereof. A pharmaceutically acceptable liquid composition according to any one of claims 4 to 8, further comprising water. A pharmaceutically acceptable liquid composition according to any one of claims 4-1. Аргининовая соль активного агента, выбранного из карбидопы и леводопы.2. Фармацевтически приемлемая жидкая или гелеобразная композиция, содержащая аргининовую соль по п.1, возможно содержащая фармацевтически приемлемый наполнитель.3. Фармацевтическ
