Question 1

Q: Purpose of adding zinc to insulin in commercial preparations for treatment of diabetes mellitus is:-

To make it long acting. ***To make it long acting*** - **Zinc** is added to insulin formulations, particularly **neutral protamine Hagedorn (NPH) insulin**, to create larger crystal complexes [1]. - These larger complexes **slow down the absorption** of insulin from the subcutaneous injection site, thereby prolonging its duration of action [2]. *To make it short acting* - **Short-acting insulins** like regular insulin are not formulated with zinc, as their purpose is rapid onset and a shorter duration. - Adding zinc would counteract the desired rapid-acting pharmacokinetic profile. *To make it fast acting* - **Fast-acting insulins** (insulin analogs) have specific amino acid modifications that alter their self-association properties to ensure rapid absorption, not the addition of zinc [2]. - Zinc actually works against the goal of fast action by promoting aggregation. *Addition of zinc makes the insulin effective orally* - Insulin is a **peptide hormone** and is generally destroyed by digestive enzymes in the gastrointestinal tract, making oral administration ineffective regardless of zinc presence [3]. - Efforts to create oral insulin involve complex delivery systems, not simple zinc addition.

Question

Purpose of adding zinc to insulin in commercial preparations for treatment of diabetes mellitus is:-

Accepted Answer

To make it long acting

Answer

To make it short acting

Answer

To make it fast acting

Answer

Addition of zinc makes the insulin effective orally

FMGE 2018 — Pharmacology