Addition of Regular Insulin to Ternary Parenteral Nutrition: A Stability Study

• Main Authors: Heloise Henry, Damien Lannoy, Patrice Maboudou, David Seguy, Thierry Dine, Pascal Pigny, Pascal Odou
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: Pharmaceutics
• Subjects: regular insulin; parenteral nutrition solutions; stability; immunoassay
• Online Access: https://www.mdpi.com/1999-4923/13/4/458

Background: Parenteral nutrition (PN) is a complex medium in which added insulin can become unstable. The aim of this study is, therefore, to evaluate the stability of insulin in PN and to identify influencing factors. Methods: A total of 20 IU/L of regular insulin was added to PN in either glass or Ethylene Vinyl Acetate (EVA) containers. A 24 h stability study was performed via an electrochemiluminescence immunoassay in different media: A ternary PN admixture, separate compartments of the PN bag and a binary admixture. This study was repeated in the absence of zinc, with the addition of serum albumin or tween and with pH adjustment (3.6 or 6.3). Insulin concentration at t time was expressed as a percentage of the initial insulin concentration. Analysis of covariance (ANCOVA) was applied to determine the factors that influence insulin stability. Results: In all PN admixtures, the insulin concentration ratio decreased, stabilising at a 60% and then plateauing after 6 h. At pH 3.6, the ratio was above 90%, while at pH 6.3 it decreased, except in the amino acid solution. ANCOVA (r² = 0.68, <i>p</i> = 0.01) identified dextrose and pH as significant factors influencing insulin stability. Conclusion: A low pH level seems to stabilise insulin in PN admixtures. The influence of dextrose content suggests that insulin glycation may influence stability.