Insulin quality questions loom large after small study

Vial samples didn’t meet standards

New research is causing quite a stir among patient advocacy groups, diabetes experts, and insulin makers.

When Alan Carter, PharmD, adjunct professor from the University of Missouri-Kansas City (UMKC) School of Pharmacy, bought vials of insulin at a number of pharmacies in Kansas and Missouri, he was alarmed that, on average, the vials had less than 1.5 of what was listed on the label and none met a minimum standard, which is 95 units per milliliter upon release. Without enough insulin, diabetes patients are at risk for serious complications.

The study tested only 18 vials of insulin. In a UMKC article posted about the research, Carter said his hope is that a larger, fully comprehensive study will be conducted sampling both the U.S. and European supply chains to examine any impact the supply chain may have on insulin. In the UMKC article, Carter said he thinks the insulin he tested could have gotten too cool or too warm somewhere between the factory and the pharmacy. This would have caused the molecules to break apart. Another theory is that insulin molecules might stick together tightly during shipping and storage, causing some clumps to remain when a dose is given.

Per the study, which was published in the Journal of Diabetes Science and Technology: “These results imply the cold supply chain [temperature-controlled supply chain] impacts insulin concentrations to a larger extent than anticipated. Patients are paying high prices for insulin and should expect to receive insulin vials with adequate insulin content in return.”