An HPLC-MS method for the quantification of new acetylcholinesterase inhibitor PC 48 (7-MEOTA-donepezil like compound) in rat plasma: Application to a pharmacokinetic study
Abstract
A simple, rapid and sensitive method based on liquid chromatography tandem mass spectrometry (LC-MS/MS) has been developed and validated for the quantitative determination in rat plasma of a new candidate for AD treatment, namely PC 48 (a 7-MEOTA-donepezil like compound) in rat plasma. Sample preparation involved pH adjustment with sodium hydroxide followed by solvent extraction with ethyl acetate:dichloromethane (80:20, v/v).
The chromatographic separation was achieved on an Ascentis Express RP-Amide column (75 mm x 2.1 mm, 2.7 mu m) with a gradient mobile phase consisting of 0.05 M aqueous formic acid and acetonitrile. Detection was carried out using positive-ion electrospray tandem mass spectrometry on an LTQXL system using the MS/MS CID (collision-induced dissociation) mode.
The method was linear in the range 0.1-1000 ng/ml(r(2) = 0.999) with a lower limit of quantitation of 0.1 ng/mL. Extraction recovery was in the range 63.5-72.1% for PC 48 and 70.5% for reserpine (internal standard, IS).
Intra- and inter-day precisions measured as relative standard deviation were below 10.8% and accuracy was from -7.2% to 7.4%. The method was successfully applied to a pharmacokinetic study involving intramuscular application of 3.86 mg/kg PC 48 to rats for the first time.
Pharmacokinetic parameters for PC 48 include C-max 39.09 +/- 4.45 ng/mL,T-max 5.00 +/- 3.08 min, AUC(0-t) 23374 +/- 4045 min ng/mL and t(1/2) 1065 +/- 246 min.