| 1921- Insulin was discovered.
1922- Bovine Insulin
1936- Protamine- a low-weight protein was used to develop a "slow-release" insulin. Protamine Zince Insulin (PZI) lasted 24-36 hours.
1950- NPH
1951- Lente Insulins (IZS), such as semilente, lente & ultralente
1956- The first antidiabetic oral drugs sulfonamide (tolbutamide, carbutamide) and biquanide (metformin, phenformin) were introduced.
1974- Chromatographic purification techniques allowed the production of highly purified animal insulin. This insulin was called "monocomponent MC" by Novo and "single peak" insulin by Eli Lily.
1975- Fully Synthetic Insulin was synthesized in laboratories of Ciba-Geigy in Basel, but because of economic reasons, large-scale production & subsequent marketing were not undertaken.
1978- Scientists from Genentech in San Fransisco, CA, using a genetically manipulated plasmid of E.Coli bacteria, succeeded in producing insulin with the same amino sequence as seen in humans.
1982- The race to produce "human" insulin sing gene technology was won by Eli Lily when the FDA approved Humulin R (rapid) and Humulin N (NPH) for the US market.
This was then followed by Novo's semisynthetic insulins, Actrapid HM & Monotard HM.
Since 1996- Different insulin anologues have been introduced, Humalog, Novolog, Lantus, Apridra, Levemir, NovoRapid, etc.  | 
