(2S)-3-(3,4-dihydroxyphenyl)-2-hydrazinyl-2-methylpropanoic acid; Carbidopa (IP); (S)-(-)-Carbidopa; (S)-3-(3,4-Dihydroxyphenyl)-2-hydrazinyl-2-methylpropanoic Acid; α-Methyldopahydrazine; Carbidopa (USP)