Other water soluble salts of NPH which may be employed to prepare such aqueous solutions include for example, alkali metal salts such as sodium; amine salts such as ethylamine, and alkanolamine salts such as ethanolamine, or any salt of NPH which has a solubility of at least 5% in water, alcohol, ester, ether or other solvents compatible with acrylic acid, and which will not deleteriously effect t