In this paper is reported the selective colorimetric detection and quantification of carbidopa, an inhibitor of aromatic amino acid decarboxylase, in the co-presence of levodopa as dopamine precursor in pharmaceutical formulations for the treatment of Parkinson's disease. The method is based on the selective condensation reaction between the hydrazine group from carbidopa and the formyl functional group of vanillin, a natural flavoring agent, in acidified alcoholic solution. The yellow color development (λmax ~ 420 nm) due to the formation of 4-hydroxy-3-methoxybenzaldazine (HMOB) was observed for carbidopa only, whereas levodopa, lacking the hydrazine group, did not color the solution, as expected. The calibration curves for two tablet formulations of levodopa in combination with carbidopa (4:1) were superimposable with levodopa/carbidopa (4:1), as well as carbidopa alone, in standard solution, i.e., the excipients and additives did not interfere with carbidopa determination, corresponding to a mean recovery about 105%. The linear dynamic range was between 5.00 and 50.0 mg L-1 with very good reproducibility within this range (CVav% about 3-4%) and very good sensitivity, with limits of quantification of about 1 mg L-1. The colorimetric method developed here is very simple, inexpensive, and effective for drug estimation and quality control of pharmaceutical formulations.
Colorimetric determination of carbidopa in anti-Parkinson drugs based on 4-hydroxy-3-methoxybenzaldazine formation by reaction with vanillin / Lettieri, Mariagrazia; Scarano, Simona; Palladino, Pasquale; Minunni, Maria. - In: ANALYTICAL AND BIOANALYTICAL CHEMISTRY. - ISSN 1618-2650. - ELETTRONICO. - 414:(2022), pp. 6911-6918. [10.1007/s00216-022-04256-4]
Colorimetric determination of carbidopa in anti-Parkinson drugs based on 4-hydroxy-3-methoxybenzaldazine formation by reaction with vanillin
Lettieri, Mariagrazia;Scarano, Simona;Palladino, Pasquale
;Minunni, Maria
2022
Abstract
In this paper is reported the selective colorimetric detection and quantification of carbidopa, an inhibitor of aromatic amino acid decarboxylase, in the co-presence of levodopa as dopamine precursor in pharmaceutical formulations for the treatment of Parkinson's disease. The method is based on the selective condensation reaction between the hydrazine group from carbidopa and the formyl functional group of vanillin, a natural flavoring agent, in acidified alcoholic solution. The yellow color development (λmax ~ 420 nm) due to the formation of 4-hydroxy-3-methoxybenzaldazine (HMOB) was observed for carbidopa only, whereas levodopa, lacking the hydrazine group, did not color the solution, as expected. The calibration curves for two tablet formulations of levodopa in combination with carbidopa (4:1) were superimposable with levodopa/carbidopa (4:1), as well as carbidopa alone, in standard solution, i.e., the excipients and additives did not interfere with carbidopa determination, corresponding to a mean recovery about 105%. The linear dynamic range was between 5.00 and 50.0 mg L-1 with very good reproducibility within this range (CVav% about 3-4%) and very good sensitivity, with limits of quantification of about 1 mg L-1. The colorimetric method developed here is very simple, inexpensive, and effective for drug estimation and quality control of pharmaceutical formulations.File | Dimensione | Formato | |
---|---|---|---|
2022 Lettieri ABC Carbidopa.pdf
accesso aperto
Tipologia:
Pdf editoriale (Version of record)
Licenza:
Open Access
Dimensione
1.28 MB
Formato
Adobe PDF
|
1.28 MB | Adobe PDF |
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.