The biphasic insulins are mixed to combine the action profiles of the component soluble and isophane insulins. For example, Human Mistard 30is composed of 30% soluble and 70% isophane insulin.
Biphasic insulins are a mixture of a short- or rapid-acting insulin with an intermediate-acting insulin. These preparations can be used to cover mealtime and basal insulin requirements, and are often used twice a day (2)
There are also insulin analogue biphasic insulins
- pre-mixed (biphasic) formulation of 30% insulin aspart and 70% protamine-crystallised insulin aspart is licensed as NovoMix 30 for the treatment of patients with diabetes
- Humalog Mix25 and Humalog Mix50, consists of a mixture of 25% or 50% insulin lispro and 75% or 50% of a protamine suspension of insulin lispro, respectively
- note that once insulin aspart or insulin lispro are co-crystallised with protamine, their absorption is slowed to a rate similar to that of an intermediate-acting conventional insulin such as isophane insulin
- a review notes that both biphasic insulin aspart and biphasic insulin lispro have similar effects on HbA1c levels and the incidence of hypoglycaemia as a comparable mixture of biphasic conventional human insulin, but reduce postprandial glucose concentrations more
Reference:
- Drug and Therapeutics Bulletin (2004); 42(10):77-80.
- MeReC Bulletin 2007;17(4).