Canine Diabetes Wiki
Iletin II NPH
NPH/isophane by Eli Lilly
U100 isophane
Action in dogs:
  • onset within 2h,
  • peak 6-12h,
  • duration 18-14h
Line: Iletin
Also known as: pork NPH, pork isophane
Similar to: Betasint Porcine NPH
Hypurin Porcine Isophane, Hypurin Pork NPH
Leo Retard, [1] Pork Insulatard [2]
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, Re-suspend
Do not use if product does not re-suspend
Do not use intravenously [3]
May be used intramuscularly, which means onset, peak and duration times are shorter.

Photo of Iletin II N-pork NPH.

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

North American brand name for Eli Lilly's 100% U100 porcine NPH/isophane insulin. [4][5]

Like all other Isophane/protamine suspended insulins, [6] it was a crystalline suspension with protamine and zinc. [7][8] No longer produced after July 2005. [9][10]

Identical insulins are: Hypurin Porcine Isophane, [11][12] Betasint Porcine NPH and Pork Insulatard [13][14] by Novo Nordisk, which was discontinued at the end of December 2007. [15]

Specifications of NPH/isophane insulin[]

British National Formulary [16] 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: [16]

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


  1. Montgomery, D. A. D.. Modern Insulin and Insulin Therapy. Royal Victoria Hospital-Belfast.
  2. 2.0 2.1 2.2 Response to Withdrawal of Novo Porcine Insulins. CP/Wockhardt UK.
  3. Maddison, Jill E.,Page, Stephen W.,Church, David B. (2008). Small Animal Clinical Pharmacology. Saunders Ltd..
  4. 4.0 4.1 Prescribing Novo Animal Insulin. Cite error: Invalid <ref> tag; name "Novo" defined multiple times with different content
  5. 5.0 5.1 Prescribing Porcine Insulin. Cite error: Invalid <ref> tag; name "Porcine" defined multiple times with different content
  6. Humulin N patient information leaflet. Eli Lilly.
  7. Iletin II N-Us Packaging Photo.
  8. Iletin II NPH-Canadian Packaging Photo.
  9. Iletin II NPH Discontinuation Notice. US Food and Drug Administration (July 2005).
  10. Iletin II NPH/Iletin II R Discontinuation Sheet. Eli Lilly.
  11. Hypurin Porcine Isophane Prescribing Information. Net Doctor uk.
  12. Hypurin Porcine Isophane. Wockhardt UK.
  13. Pork Insulatard Patient Information. Net Doctor uk.
  14. 14.0 14.1 Patient Information Leaflet-Pork Insulatard. Novo Nordisk.
  15. Pork Insulatard Discontinuation Notice. Novo Nordisk.
  16. 16.0 16.1 British National Formulary-Isophane/NPH Insulin Definition. InChem. Cite error: Invalid <ref> tag; name "InChem" defined multiple times with different content
  17. Hypurin Bovine Isophane Patient Information. Net Doctor uk.
  18. Hypurin Bovine Isophane. Wockhardt UK.
  19. Prescribing Bovine Insulin

More information[]

Related Pages
Hypurin pork n
Pork Insulatard
Betasint Porcine NPH
Hypurin Porcine Isophane
Pork Insulatard