HUMULIN N (human insulin [rDNA origin] isophane) suspension is a human insulin suspension. Human insulin is produced by recombinant DNA technologyutilizing a non-pathogenic laboratory strain of Escherichia coli. HUMULIN N is a suspension of crystals produced from combining human insulin and protamine sulfate under appropriate conditions for crystal formation. The amino acid sequence of HUMULIN N is identical to human insulin and has the empirical formula C257H383N65O77S6 with a molecular weight of 5808.
HUMULIN N is a sterile white suspension. Each milliliter of HUMULIN N contains 100 units of insulin human, 0.35 mg of protamine sulfate, 16 mg of glycerin, 3.78 mg of dibasic sodium phosphate, 1.6 mg of metacresol, 0.65 mg of phenol, zinc oxide content adjusted to provide 0.025 mg zinc ion, and Water for Injection. The pH is 7.0 to 7.5. Sodium hydroxide and/or hydrochloric acid may be added during manufacture to adjust the pH.