In hospital intensive care units, insulin is a critical therapeutic used to maintain tight glycemic control. While it is typically supplied at 100 units\/mL, clinical protocols dilute it to 1 unit\/mL for continuous infusion, commonly known as the insulin infusion protocol (IIP). At these low concentrations, ensuring stability becomes challenging, especially when aggregation or surface adsorption may occur in saline bags, containers, or IV tubing.<\/p>\n\n\n\n
A study led by Professor Lu\u00eds Maur\u00edcio Trambaioli R. Lima at Universidade Federal do Rio de Janeiro<\/a> addressed this using dynamic light scattering (DLS), a technique known for its exceptional sensitivity to early-stage aggregation. Using a DynaPro DLS Instrument<\/a>, the team evaluated insulin stability under conditions mimicking real clinical workflows.<\/p>\n\n\n\n DLS measures fluctuations in scattered light caused by particles undergoing Brownian motion. The physics of light scattering means larger species scatter disproportionately more light, enabling highly sensitive aggregate detection. To establish detection limits, the researchers created a reference sample of aggregated insulin as a benchmark, then diluted it stepwise to determine how far the signal could still be detected.<\/p>\n\n\n