Nondestructive Quantitative Inspection of Drug Products Using Benchtop NMR Relaxometry—the Case of NovoMix® 30

Batch-level inference-based quality control is the standard practice for drug products. However, rare drug product defects may be missed by batch-level statistical sampling, where a subset of vials in a batch is tested quantitatively but destructively. In 2013, a suspension insulin product, NovoLog® Mix 70/30 was recalled due to a manufacturing error, which resulted in insulin strength deviations up to 50% from the labeled value. This study analyzed currently marketed FlexPen® devices by the water proton transverse relaxation rate using a benchtop nuclear magnetic resonance relaxometer. The water proton transverse relaxation rate was found to be sensitive to detecting concentration changes of the FlexPen® product. These findings support the development of vial-level verification-based quality control for drug products where every vial in a batch is inspected quantitatively but nondestructively.