Lipid emulsion content and vitamin A stability in TPN admixtures

Vitamin A stability in TPN regimens may be influenced by the different lipid content in lipid, 3-in-1 and aqueous admixtures. In this study vitamin A losses were investigated by HPLC, in a paediatric lipid emulsion, a paediatric 3-in-1 admixture, an adult aqueous glucose/amino acid admixture and an adult 3-in-1 admixture. The admixtures were stored in PVC containers under typical storage and administration conditions. Pharmaceutically significant vitamin A losses under storage conditions occurred only from the paediatric 3-in-1 admixture. These losses could have been caused by the presence of trace elements from Ped-el^®. On exposure to ward light and temperature, the only admixture with a t_90% less than 24 h was the adult aqueous admixture. Under these conditions there was an inverse linear correlation between fat content and vitamin A loss. Fat emulsions in TPN afford protection from light to vitamin A. Hence, the vitamin should be added to lipid emulsions where possible.