Humulin is the brand name for a group of biosynthetic humaninsulin products, developed by Arthur Riggs, working with Genentech in 1978 (Generic names regular insulin, insulin isophane and the Lente series consisting of Lente (known generically as insulin zinc suspension) is actually a mixture of Ultralente and Semilente) and later acquired by Eli Lilly and Company, the company who arguably facilitated the product's approval with the U.S. Food and Drug Administration. The Lente series was discontinued by Lilly in 2005. Prior to the development of synthesized human insulin, patients were dependent on animal insulin which was more costly, less accessible, and caused infections in some patients.
Humulin is synthesized in a laboratory strain of Escherichia coli bacteria which has been genetically altered with recombinant DNA to produce biosynthetic human insulin. Humulin R consists of zinc-insulin crystals dissolved in a clear fluid. The synthesized insulin is then combined with other compounds or types of insulin which affect its shelf life and absorption. For example, Humulin N is combined with protamine to extend the time-activity profile of Humulin R for an extended period.
Humulin by itself is a short-acting insulin. Humulin R, like many other form of injectable insulin, is intended for subcutaneous injection, so it should not be used intramuscularly, since its dispersion in the rest of the body would take more time.
It is currently sold by Eli Lilly under different types:
Humulin R (REGULAR human insulin injection [rDNA origin]) is a short-acting insulin that has a relatively short duration of activity as compared with other insulins.
Humulin R Regular U-500 (Concentrated) insulin human injection, USP (rDNA Origin) is a stronger concentration (500 units/mL) of Humulin R.
Humulin N (human NPH insulin injection [rDNA origin]) is an intermediate-acting insulin with a slower onset of action and a longer duration of activity than Humulin R.
Humulin 70/30 (70% human insulin isophane suspension, 30% human insulin injection [rDNA origin]) is a mixture insulin. It is an intermediate-acting insulin combined with the onset of action of Humulin
Humulin 50/50 (50% human insulin isophane suspension, 50% human insulin injection [rDNA origin]) is a mixture insulin. It is an intermediate-acting insulin combined with the onset of action of Humulin R.
Humulin is identical in chemical structure to human insulin.