Canine Diabetes Wiki
Iletin I NPH
NPH/Isophane by Eli Lilly
Bovine 85% Porcine 15%
U100 Isophane
Action in dogs:
  • onset within 2h,
  • peak 6-12h,
  • duration 18-24h
Line: Iletin
Also known as:
Similar to:
Use and Handling:
Shelf Life: 24 months Type: cloudy
When Opened: 28 days room temp.
In Pen: N/A
Notes: Protect from light and heat
Do Not Freeze,
Do not use if product does not re-suspend
Do not use intravenously [1]
See Hypurin Bovine Isophane or Betasint Bovine NPH for current handling notes for bovine NPH insulin.

Iletin I N

Iletin I NPH.isophane beef/pork insulin. The insulin was discontinued by Lilly in 1998.

Lilly human insulins1992charts

Lilly insulin products-1992. This insulin is shown as Iletin I NPH.

Note that some countries have the brand name in U40 strength.

An 85% beef. 15% pork NPH/isophane suspended insulin formerly made by Eli Lilly[2]

Like all other isophane/protamine suspended insulins, [3] it was a crystalline suspension with protamine and zinc. [4]

The closest currently marketed equivalent is Hypurin Bovine Isophane [5][6], made by CP Pharma [7] and Betasint Bovine Lente by Beta Laboratorios.

Specifications of NPH/isophane insulin[]

British National Formulary [8] defines this type as: A sterile suspension bovine or porcine or of human insulin in the form of a complex obtained by the addition of protamine sulphate or another suitable protamine.

British Pharmacoepia and United States Pharmacopia definitions: [8]

Isophane Insulin

Sterile buffered suspension of insulin in the form of a complex obtained by addition of suitable protamine. Prepared from crystalline insulin. pH 6.9 - 7.5 iso-osmotic with blood. Contains for each 100 units of insulin, 300 - 600 g protamine sulphate and not more than 40 g zinc, a suitable bactericide and sodium phosphate as buffering agent.

USP specification: Sterile suspension of zinc insulin crystalline and protamine sulphate in buffered water for injection. Solid phase contain crystals of insulin protamine and zinc; 40, 80, 100 units/ml. Contains glycerol, metacresol, phenol sodium phosphate and zinc.

NPH/isophane insulins[]

The following commercial insulins are all generically NPH insulins:

Other commonly used names are:

  • NPH insulin, NPH
  • isophane insulin


More information[]