Endotoxin Detection in Magnetic Resonance Imaging Contrast Agent Using Optimising Chromogenic Limulus Amebocyte Lysate Assay

Endotoxin contamination in magnetic resonance imaging (MRI) contrast agents can pose a risk to patient safety causing immune reactions. Strict endotoxin limits are enforced for implants and catheters inserted into the body, but there are not clear rules for MRI contrast agents. Here, we investigated the efficacy of chromogenic LAL assay test for screening endotoxin activity in MRI contrast media manufactured in Malaysia. The powdered agent was dissolved in water for injection and endotoxin levels were measured. The coefficient of efficiency value for the standard curve, exhibiting r² ≥ 0.98, along with the absence of interfering substances and endotoxin activity below the regulatory threshold of 0.5 EU/mL, support the conclusion that the agent is unlikely to be pyrogenic or induce pyrogenic effect.