Canine Diabetes Wiki
Leo Retard[1]
NPH/isophane by Novo Nordisk
U100 isophane
Action in dogs:
  • onset within 2h,
  • peak 6-12h,
  • duration 18-14h
Line: Nordisk
Also known as: Pork Insulatard [2], pork NPH, pork isophane
Similar to: Betasint Porcine NPH
Hypurin Porcine Isophane, Hypurin Pork NPH
Iletin II NPH
Use and Handling:
Shelf Life: 36 months Type: cloudy
When Opened: 6 weeks room temp.
In Pen: 6 weeks room temp.
Notes: Protect from light and heat
Do Not Freeze, Re-suspend
Do not use if product does not re-suspend

Cartridges in use are not to be refrigerated
Do not use intravenously [3]
May be used intramuscularly, which means onset, peak and duration times are shorter.

Human Activity Profiles Various Insulins

Time activity profile for Pork Insulatard-Leo Retard would be an identical product.

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

Leo Retard was a porcine NPH/Isophane insulin [4] [5] made by Nordisk. [1]

It is similar to CP Pharma's Hypurin Porcine Isophane, [6][7] to Beta's Betasint Porcine NPH and to the now-defunct Eli Lilly product Iletin II NPH. [8][9][10]

Like all other isophane/protamine suspended insulins [11], it is a crystalline suspension with protamine and zinc.

After December, 2007, Novo Nordisk no longer offered Pork Actrapid in the UK; [12][13][14][15][16] according to the Novo Nordisk Australasia Home Page, [17] it was discontinued there by December, 2006. Those using it now order Hypurin Porcine Isophane from CP Pharma [18] or Betasint Porcine NPH from Beta Laboratorios.

Specifications of NPH/isophane insulin[]

British National Formulary [19] 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: [20]

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. 1.0 1.1 Montgomery, D. A. D.. Modern Insulin and Insulin Therapy. Royal Victoria Hospital-Belfast. Cite error: Invalid <ref> tag; name "Montgomery" defined multiple times with different content
  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. Pork Insulatard Patient Information.
  5. Patient Information Leaflet-Pork Insulatard. Novo Nordisk.
  6. Hypurin Porcine Isophane. Wockhardt UK.
  7. Hypurin Porcine Isophane Patient Information. Net
  8. Iletin II N Discontinuation. US-FDA (July 2000).
  9. 9.0 9.1 Prescribing Novo Animal Insulins. Cite error: Invalid <ref> tag; name "Novo" defined multiple times with different content
  10. 10.0 10.1 Prescribing Porcine Insulins. Cite error: Invalid <ref> tag; name "Porcine" defined multiple times with different content
  11. Humulin N.
  12. Novo Pork Insulin Discontinuation Information. Diabetes UK.
  13. Insulin Discontinuations--UK. NHS.
  14. Novo Nordisk Discontinues Animal Insulin Worldwide. Forum Insulin Schweiz.
  15. Pork Insulin Discontinuation Notice. NovoNordisk UK.
  16. Novo Pork Insulin Discontinuations. Novo Nordisk (2007).
  17. Novo Nordisk Australasia Home Page--Novo Pork Insulin Discontinuation. Novo Nordisk.
  18. Wockhardt/Hypurin Insulin Substitutes. NHS.
  19. British National Formulary-Isophane/NPH Insulin Definition. InChem.
  20. British Pharmacoepia (BP) & United States Pharmacoepia (USP)-Isophane/NPH Insulin Defined. InChem.
  21. Hypurin Bovine Isophane Patient Information. Net
  22. Hypurin Bovine Isophane. Wockhardt UK.
  23. Prescribing Bovine Insulin.
  24. Patient Information Leaflet-Pork Insulatard. Wockhardt UK.

More Information[]

Related pages
Hypurin pork r
Pork Insulatard
Betasint Porcine NPH
Hypurin Porcine Isophane
Pork Insulatard