Disclosed is a formulation for parenteral administration comprising insulin that comprises a pH memory between 1 to 4 or between 6 to 8 and an aprotic polar solvent, wherein the insulin is solubilized in the aprotic polar solvent, wherein the solubilized insulin comprises stable monomeric or dimeric forms of insulin or mixtures thereof, and wherein the water content of the formulation is equal to or less than 15% w/v.
