A liquid composition which comprises an organic liquid diluent and at least one non-ionic cellulose ether having a viscosity of up to 2.33 mPa·s, measured as a 2 wt.-% solution in water at 20° C., is stable over an extended time period. The liquid composition is useful for preparing a solid dispersion comprising at least one active ingredient in at least one cellulose ether by spray-drying. Alternatively a solid dispersion can be produced by blending and extruding at least one active ingredient, at least one cellulose ether having a viscosity of up to 2.33 mPa·s and optionally one or more adjuvants.