|Winthrop Comb 50|
|R/Neutral/NPH/Isophane Mix by Aventis|
| Action in dogs:
| Also known as: Insuhuman Comb 50|
Insuman Comb 50
| Similar to: Huminsulin 50/50,Humulin M5|
Humulin 50/50,Humulina 50/50, Humuline 50/50
Actraphane 50/50, Mixtard 50, Penmix 50 
Names of Lilly r-DNA/GE/GM insulins worldwide
|Use and Handling:|
|Shelf Life: 24 months||Type: cloudy|
|When Opened: 4 weeks room temp.|
|In Pen: 4 weeks room temp.|
| Notes: Protect from light and heat|
Do Not Freeze, Resuspend
Do not use if product does not re-suspend
Do not use intravenously 
Note that some countries have the brand name in U40 strength.
This is an Aventis mixed, intermediate-acting insulin  comprised of 50% R/neutral and 50% NPH/isophane crystal insulin , one of its Winthrop  line of products,  which is identical to its Insuman line. 
Eli Lilly produced a comparable insulin for North America: Humulin 50/50;  they also formerly produced this insulin in the EU & UK under the brand name Humulin M5.  M5 was discontinued in July 2004.  Other similar Lilly insulins are Humulina 50/50 and Humuline 50/50.
Mixed insulins cover a wide range as they can be animal origin, r-DNA/GE/GM origin or analog insulins. The non-analog mixed insulins are made up of intermediate-acting NPH/isophane insulin and short-acting R/neutral. normal insulin. The analog mixes are made from intermediate-acting protamine-suspended analog insulin (suspended similar to NPH/isophane insulin) and fast-acting analog insulin. They can also vary in the fraction (amount or percent) of the two types (R/neutral and NPH/isophane) of insulin used to make a non-analog mix, and in the percentage of fast/rapid-acting analog insulin and slower-acting protamine suspended analog insulin.
For some reason, those in the US choose to list the slower, NPH/isophane based insulin fraction first, such as Humulin or Novolin 70/30. The rest of the world gives the faster insulin top billing and the result is 30/70. Regardless of how this is written, it means that the insulin is made up of 70% NPH/isophane insulin and 30% R/neutral insulin.
The most common mixes are 70/30 (30/70) (non analog) or 75/25 (25/75) (analog). There are no currently-marketed mixes which combine insulins of different origins. Eli Lilly's form of beef/pork Iletin and Novo Nordisk's Lentard were discontinued some time ago. Here are the most common ones that could cause confusion:
|Non-Analog Mixed Insulins|
|Insulin Is||Expressed As||Expressed As|
|10% R/Neutral Insulin|
90% NPH/Isophane Insulin
|20% R/Neutral Insulin|
80% NPH/Isophane Insulin
|30% R/Neutral Insulin|
80% NPH/Isophane Insulin
|40% R/Neutral Insulin|
60% NPH/Isophane Insulin
|50% R/Neutral Insulin|
50% NPH/Isophane Insulin
- ↑ Penmix 50. Medsafe NZ.
- ↑ Maddison, Jill E.,Page, Stephen W.,Church, David B. (2008). Small Animal Clinical Pharmacology. Saunders Ltd..
- ↑ Patient Information Leaflet-Insuman Comb 50. Sanofi-Aventis.
- ↑ Scientific Discussion-Mixtard. EMEA.
- ↑ Winthrop Insulins. EMEA.
- ↑ Aventis Poster-Insuman & Lantus Insulins. Sanofi-Aventis.
- ↑ Scientific Discussion-Insuman. EMEA.
- ↑ Humulin 50/50-NPH;R Human Insulin. Revolution Health.
- ↑ Lilly EU/UK Product Sheet & Time Activity Profiles. Eli Lilly.
- ↑ Withdrawal of Humulin M5. Diabetes UK (July 2004).
- ↑ Scientific Discussion-Actraphane. EMEA.
- ↑ Insulins & Mixtures. NHS.