Experimental data are presented that demonstrate the dependence of the glow discharge parameters in argon-hydroxyl mixtures, including the UV emission efficiency, stability, and duration of the discharge, on the working mixture preparation conditions. Principles allowing the preparation of optimum inert gas-hydroxyl mixtures are established. The main point is to suppress the possible formation of water and/or hydroxyl complexes capable of hindering the realization of optimum conditions for the 306.4 nm OH resonance band excitation in the discharge stage.