Mechanism of action<unk>  differs from human insulin by replacing asparagine with glycine in position 21 of the A-chain and by carboxy-terminal extension of B-chain by 2 arginine residues. The arginine amino acids shift the isoelectric point from a pH of 5.4 to 6.7, making the molecule more soluble at an acidic pH and less soluble at physiological pH. The isoelectric shift also allows for the subcutaneous injection of a clear solution. The glycine substitution prevents deamidation of the acid-sensitive asparagine at acidic pH. In the neutral subcutaneous space, higher-order aggregates form, resulting in a slow, peakless dissolution and absorption of insulin from the site of injection. It can achieve a peakless level for at least 24 hours. Acceptance and repartition in the body<unk>  is formulated at an acidic pH 4, where it is completely water-soluble. After subcutaneous injection of the acidic solute (which can cause discomfort and a stinging sensation), when a physiologic pH (approximately 7.4) is achieved the increase in pH causes the insulin to come out of solution resulting in the formation of higher order aggregates of insulin hexamers. The higher order aggregation slows the dissociation of the hexamers into insulin monomers, the functional and physiologically active unit of insulin. This gradual process ensures that small amounts of<unk>  are released into the body continuously, giving an almost peakless profile.
Insulin glargine
Insulin aspart
Insulin glulisine
Lente insulin
Regular insulin
Insulin detemir
NPH insulin
Insulin lispro