Which insulin preparation has the slowest and most prolonged onset-free-peak absorption profile due to formation of hexameric microprecipitates at physiological pH?

• A Insulin glargine (pH-adjusted formulation)
• B Insulin degludec (forming multi-hexameric chains after injection) ✓
• C Insulin detemir (fatty acid acylation facilitating albumin binding)
• D Insulin glargine provides the flattest profile through precipitate dissolution, not multi-hexameric chain formation

Explanation

Insulin degludec, a basal ultra-long-acting insulin (duration >42 hours), forms stable multi-hexameric chains via phenol and zinc interactions at the injection site after subcutaneous administration. These large depots dissociate very slowly, releasing insulin monomers over an exceptionally prolonged, peakless period. Insulin glargine forms microprecipitates at physiological pH (after injection from its acidic pH4 formulation), providing a ~24-hour flat profile. Detemir is protracted by albumin-binding via fatty acid acylation. Degludec's peakless ultra-long profile distinguishes it from both.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.