SUN-627 A Test for Variation in Insulin Concentrations at the Wilford Hall Ambulatory and Surgical Center

Abstract

BackgroundWilford Hall Ambulatory and Surgical Center is the Department of Defense’s largest outpatient ambulatory surgical center serving over 55,000 patients, and is the U.S. Air Force’s flagship medical facility for outpatient care.As with the measurement of any medication concentration or lab value, there is some reasonable expectation that there may be some variability between the reported value and the objective measurement. However, expectations are that variability should be minimal in order to ensure reliable doses of medication. In the case of diabetes management, insulin concentration variability should be kept to a minimum for both its life-saving and stress-mitigating effects. Insulin in the correct doses is lifesaving for type 1 Diabetes, so understandably, the impact of degraded insulin is catastrophic. In both type I and type II diabetes, “diabetes distress” can lead to poor self management and is linked to higher A1C levels. A study published in 2017 testing insulin after receipt from their cold supply chain found shockingly low concentrations of insulin. Recent literature published in the Journal of Diabetes Science and Technology reported that insulin concentrations in randomly tested vials not only failed to meet a pre-established concentration standard per unit of insulin, but also had concerning variability. The prevalence of Diabetes in the Department of Defense population is approaching 20%, making the impact of degraded insulin concerning. There are expectations of variability in any medications prescribed, but the FDA states that the expected insulin concentration should be 95% or greater.MethodsOverall, 40 vials representing two different types of insulin (20 vials of Novolog and 20 vials of Lantus) were collecting from the military pharmacy and transported to the clinical research laboratory for analysis. Following baseline analysis, half of the vials were stored in refrigerated conditions of 2-8 degrees Celsius; the other half were stored at room temperature according to manufacturer’s directions.ResultsAt the laboratory, all vials underwent initial analysis to determine concentration at baseline. The Novolog insulin was found to have a concentration range of 105.1% to 107.7% and the Lantus insulin concentration was 99.0% to 103.9%. Thus, all vials met the minimum concentration of 95 U/ml at time of baseline testing. Vials will be tested weekly to determine if degradation occurs under refrigeration and at room temperature.DiscussionGiven the high cost of insulin and the high impact on the health of the person with diabetes, assurance of a minimum of 95 U/ml must be met. If this is not met, investigation of the cold supply chain should identify the source of the problem and address it. Our study demonstrates that Novolog and Lantus were meeting the minimum concentration upon receipt at the pharmacy.