Role of DMSO and Tween 20 in Acetylecholinesterase Inhibitory Activity of Donepezil Hydrochloride

Abstract

Improving the solubility of non-polar tested compounds is essential for evaluating in vitro acetylcholinesterase (AChE) activity using modified Ellman’s method. Unfortunately, dimethyl sulfoxide (DMSO), a widely used solvent for dissolving hydrophobic compounds, displayed the inhibitory activity against AChE, resulting In its limited application. For this reason, Tween 20 was considered as a cosolvent. The aim of this study was to optimize the final concentration of DMSO in combination with Tween 20 in AChE activity determination. Donepezil HCI ().01 mg/mL) was used as the reference for investigating AChE inhibitory activity in 11 different combined solvents. The results showed that 2% v/v Tween 20 had no significant change in AChE inhibition of donepezil HCI. Furthermore, the maximum concentration of DMSO which can be used in the reaction mixture without significant interference was 0.1% v/v. Accordingly, the solution of 0.1% v/v DMSO and 2% v/v Tween 20 is suitable for improving non-polar materials solubility in modified Ellman’s test