Storage of mixtures for total parenteral nutrition--long-term stability of a total parenteral nutrition mixture

Abstract

A TPN mixture containing amino acids, dextrose, electrolytes, and trace elements was analysed dor chemical stability during storage at 4 degrees C for 6 months. Dextrose, electrolytes, and trace elements appeared to be stable during the storage period. However, this study established that some amino acids were not stable for more than 2 months. After 6 months, the amino acids except tyrosine, lysine, and histidine were degraded by more than 10%. The most pronounced degradation was seen with alanine, proline, threonine, methionine, glycine, and arginine. Tryptophan was, in spite of the presence of bisulphite, one of the more stable amino acids. Further investigations are needed to identify the degradation products. pH and colour of the solution remained unchanged during the study and no precipitation was observed.