The prolonged action of insulin detemir compared with neutral soluble insulin depends primarily on which property?

• A Formation of multi-hexameric chains at the injection site
• B Precipitation as micro-crystals at neutral pH
• C Myristic acid side chain causing reversible albumin binding ✓
• D Addition of protamine forming an insoluble complex

Explanation

Detemir is acylated at lysine C29 with a myristic acid (B14 fatty acid) residue. This allows reversible binding to serum albumin, creating a slow-release reservoir that prolongs action to roughly 12 to 24 hours with a flatter profile. Degludec uses dihexamer formation via a different acylation strategy, glargine relies on isoelectric precipitation, and NPH uses protamine. Detemir's albumin binding is the distinguishing feature asked here.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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