Stability of cocarboxylase in parenteral nutrition mixtures stored in multilayer bags

The aim of this study was to determine the stability of cocarboxylase, a thiamine derivative employed as a vitamin B1 source in multivitamin additives, in parenteral nutrition (PN) mixtures containing different commercial amino acid infusions. In particular, the influence of a metabisulphite-containing amino acid product, Freamine III, was investigated. A liquid chromatographic assay method for cocarboxylase was developed and employed to investigate cocarboxylase degradation during extended storage of PN mixtures at 5 degrees C in multilayered bags. Results indicated that cocarboxylase was relatively stable over the 28-day storage period in PN mixtures containing Synthamin or Vamin products as amino acid source. In contrast, degradation was accelerated in PN mixtures containing Freamine III, suggesting that cocarboxylase is degraded by sodium metabisulphite, showing similar sensitivity to thiamine.