Monograph: |
Bovine porcine isophane insulin
Bovine insulin differs from human insulin by 1 amino acid in the B
chain & 2 amino acids in the A chain.
Early commercial insulins were obtained by extrac-
tion from bovine or porcine or mixed bovine and
porcine pancreases and were purified by recrystalli-
sation only. Insulins obtained by such methods were
often termed 'conventional insulins' to distinguish
them from insulins which have undergone further
purification processes.
In order to prolong the duration of action of insulin,
preparations may be formulated as suspensions in 2
general ways. The first involves complexing insulin
with a protein from which it is slowly released; ex-
amples are protamine zinc insulin, which contains
an excess of protamine, and isophane insulin, which
contains equimolecular amounts of insulin
and protamine.
The action starts within 2 hrs, peak effect lasts for 4 to 12 hrs and total
effect lasts for about 24 hrs.
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