Biphasic insulins are mixtures of insulin providing for both immediate and prolonged actions. These mixtures form intermediate acting insulins. Usually, Human insulin R is available in combination with NPH or isophane insulin in 30/70 ratio. Other insulins are also available as biphasic insulins for example insulin aspart/insulin aspart protamine, insulin lispro/insulin lispro protamine. Biophasic insulins may be available in 30/70, 50/50, 25/75 ratio. Insulins available in combination can only be used subcutaneously. Combination insulin or Biphasic insulins are not for intravenous use. Pharmacokinetics of insulin aspart/insulin aspart protamine combination, insulin lispro/insulin lispro protamine combination and soluble human insulin R/isophane insulin combination is different from each other. So, these can be given either once daily, twice daily and thrice daily depending upon the required glycemic control.

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