Modified high-performance liquid chromatography with electrochemical detection method for plasma measurement of levodopa, 3-O-methyldopa, dopamine, carbidopa and 3,4-dihydroxyphenyl acetic acid.
Plasma measurements of levodopa and its major metabolites including dopamine and 3-O-methyldopa have been limited by cumbersome methods and poor sensitivity within relatively narrow ranges of plasma levels. We now report a modification of an HPLC method that permits concomitant measurements of a wide range of concentrations of levodopa, dopamine (DA), carbidopa, 3-O-methyldopa (3-OMD) and 3,4-dihydroxyphenyl acetic acid (DOPAC) from one HPLC injection. The recoveries ranged from 77 to 107% with an intra-day precision around 5% (CV) and inter-day CV's about 10-20%. This validated method will simplify pharmacokinetic studies of levodopa and its metabolites for mechanistic studies or therapeutic clinical monitoring which play a crucial role in development of strategies to prolong motor benefits from individual doses and reduce involuntary movements called dykinesias.
Karimi
Morvarid
M
Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA.
Carl
Juanita L
JL
Loftin
Susan
S
Perlmutter
Joel S
JS
D015102:3,4-Dihydroxyphenylacetic Acid / Q000097:blood*; D002138:Calibration; D002230:Carbidopa / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004298:Dopamine / Q000097:blood*; D004563:Electrochemistry / Q000379:methods*; D007980:Levodopa / Q000097:blood* / Q000493:pharmacokinetics; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000097:blood
D015102:3,4-Dihydroxyphenylacetic Acid; D014443:Tyrosine; D007980:Levodopa; D002230:Carbidopa; C008404:3-methoxytyrosine; D004298:Dopamine