Concentration and Chemical Stability of Commercially Available Insulins: A High-Resolution Mass Spectrometry Study.

Abstract

Adequacy of insulin concentration in commercially available insulin formulations has recently been challenged. We therefore repeatedly evaluated insulin content and stability of 58 insulin vials containing 5 different insulin formulations (human insulin, standard/faster-acting insulin aspart, insulin lispro, and insulin glargine) over a period of 85 days. High-resolution mass spectrometry was used to quantify intact monomeric insulin in glass vials and plastic pump cartridges exposed to three different temperatures (4°C, 22°C, 37°C), simulating real-life conditions. In all cases, measured insulin concentration was in accordance with FDA and European Medicines Agency (EMA) requirements without evidence of chemical instability.