Food and Drug Regulations

C.04.590 The insulin preparation “Protamine Zinc Insulin” shall be a sterile white suspension in a buffered aqueous medium, containing insulin modified by the addition of protamine and zinc, shall have a pH of not less than 7.1 and not more than 7.4, and shall contain,

• (a) weight by volume,

  • (i) not less than 0.15 per cent and not more than 0.25 per cent anhydrous disodium phosphate,

  • (ii) not less than 1.4 per cent and not more than 1.8 per cent glycerin, and

  • (iii) either not less than 0.18 per cent and not more than 0.22 per cent cresol, or not less than 0.22 per cent and not more than 0.28 per cent phenol; and

• (b) as determined by an acceptable method, for each 1,000 International Units of insulin,

  • (i) not more than 12.5 milligrams of total nitrogen,

  • (ii) not less than 10.0 milligrams and not more than 15.0 milligrams of protamine,

  • (iii) not less than 1.7 milligrams and not more than 2.5 milligrams of zinc.