TY - JOUR
T1 - Effect of charge of quaternary ammonium cations on lipophilicity and electroanalytical parameters
T2 - Task for ion transfer voltammetry
AU - Poltorak, Lukasz
AU - Sudholter, E.J.R.
AU - de Smet, Louis C.P.M.
PY - 2017/7/1
Y1 - 2017/7/1
N2 - The electrochemical behavior of three differently charged drug molecules (zwitter-ionic acetylcarnitine, bi-cationic succinylcholine and tri-cationic gallamine) was studied at the interface between two immiscible electrolyte solutions. Tetramethylammonium was used as a model mono cationic molecule and internal reference. The charge and molecular structure were found to play an important role in the drug lipophilicity. The studied drugs gave a linear correlation between the water – octanol (logPoctanol) partition coefficients and the electrochemically measured water – 1,2-dichloroethane (logPDCE) partition coefficients. Comparison with tetraalkylammonium cations indicating that the correlation between logPoctanol and logPDCE is molecular structure dependent. The highest measured sensitivity and lowest limit of detection were found to be 0.543 mA·dm3·mol− 1 and 6.25 μM, respectively, for the tri-cationic gallamine. The sensitivity for all studied ions was found to be a linear function of molecular charge. The dissociation constant of the carboxylic group of zwiter-ionic acetylcarnitine was calculated based on voltammetric parameters and was found to be 4.3. This study demonstrates that electrochemistry at the liquid – liquid interface is powerful technique when it comes to electroanalytical or pharmacokinetic drug assessment.
AB - The electrochemical behavior of three differently charged drug molecules (zwitter-ionic acetylcarnitine, bi-cationic succinylcholine and tri-cationic gallamine) was studied at the interface between two immiscible electrolyte solutions. Tetramethylammonium was used as a model mono cationic molecule and internal reference. The charge and molecular structure were found to play an important role in the drug lipophilicity. The studied drugs gave a linear correlation between the water – octanol (logPoctanol) partition coefficients and the electrochemically measured water – 1,2-dichloroethane (logPDCE) partition coefficients. Comparison with tetraalkylammonium cations indicating that the correlation between logPoctanol and logPDCE is molecular structure dependent. The highest measured sensitivity and lowest limit of detection were found to be 0.543 mA·dm3·mol− 1 and 6.25 μM, respectively, for the tri-cationic gallamine. The sensitivity for all studied ions was found to be a linear function of molecular charge. The dissociation constant of the carboxylic group of zwiter-ionic acetylcarnitine was calculated based on voltammetric parameters and was found to be 4.3. This study demonstrates that electrochemistry at the liquid – liquid interface is powerful technique when it comes to electroanalytical or pharmacokinetic drug assessment.
KW - Acetylcarrnitine
KW - Gallamine
KW - ITIES
KW - Muscle relaxants
KW - Partition coefficient
KW - Succinylcholine
UR - http://resolver.tudelft.nl/uuid:80126e66-13d2-4726-b974-e79bb1b98990
UR - http://www.scopus.com/inward/record.url?scp=85019156712&partnerID=8YFLogxK
U2 - 10.1016/j.jelechem.2017.04.051
DO - 10.1016/j.jelechem.2017.04.051
M3 - Article
AN - SCOPUS:85019156712
SN - 1572-6657
VL - 796
SP - 66
EP - 74
JO - Journal of Electroanalytical Chemistry
JF - Journal of Electroanalytical Chemistry
ER -