Natural deep eutectic solvents, new green solvents, are being investigated as alternative solvents for dissolving active pharmaceutical ingredients. The development of an effective antidote for poisoning by organophosphates (OPs), irreversible inhibitors of the essential enzyme acetylcholinesterase (AChE), has been a subject of many research. The focus is on the so-called centrally active oxime reactivators of phosphylated AChE like poorly water-soluble oxime RS-194B. In this study, the solubility of RS-194B oxime in natural deep eutectic solvents has been predicted by the COSMOtherm program and experimentally determined using high efficient liquid chromatography. Natural deep eutectic solvent citric acid: glucose=1:1 with 30 % water content has resulted with best solubility of oxime RS-194B. The stability of oxime RS-194B formulation in the selected natural deep eutectic solvent has been monitored during one month period at temperatures of 4 °C and 25 °C where no difference in the stability of these formulations was observed. Before determining the effect of RS-194B oxime formulation in the selected solvent on the reactivation kinetics of AChE inhibited by OPs sarin and VX, the effect of the solvent itself on the AChE was determined. It was found that the selected solvent inhibited AChE completely, and in order for AChE to maintain more than 90 % activity, its content has to be kept below 0,2 %. The affinity of AChE and phosphylated AChE is higher for the binding of oxime dissolved in the selected solvent than in water. The oxime, regardless of the solvent, is a better reactivator of VX- than sarin-inhibited AChE. However, the maximal first-order reactivation rate of phosphylated AChE is lower with RS-194B in the selected solvent than with RS-194B dissolved in water. Therefore, although the use of the selected solvent resulted in better solubility of RS-194B oxime compared to water as the reference solvent and improved the affinity of AChE for RS-194B, the solvent citric acid: glucose=1:1, 30 % water, is not suitable for preparing the RS-194B formulation for in vivo application due to its inhibitory effect on the enzyme, viscosity and low pH.