Stability of Total Parenteral Nutrition (TPN) Mixtures
The results of the study contributed to the understanding of vitamin E delivery in PN mixtures and the loss or degradation of admixed nutrients.
”Stability of vitamin E isomers in TPN regimens
The problem
Parenteral Nutrition (PN) is the practice of feeding a person intravenously bypassing the usual process of eating and digestion.
Vitamin E exists in a number of isomers, in particular alpha, delta and gamma forms. Tocopherol is a class of chemical compounds of which many have vitamin E activity. The compound alpha-tocopherol is the most biologically active. Additives in PN mixtures are formulated using alpha-tocopherol but fat emulsions in the mixtures contain natural levels of the tocopherol isomers.
The solution
Our pharmacists developed an assay for tocopherol isomers, examinedthe stability of naturally occuring isomers and comparedthe different commercial sources of amino acids.
The PN mixtures were prepared and stored for 28 days. At 7 day intervals samples were removed for analysis of the tocopherol isomers by a stability-indicating HPLC method.
The outcome
The results indicated that isomers share similar stability profiles in PN mixtures. The naturally occurring tocopherol content of fat emulsions proved to contribute to the overalldelivery of vitamin E provided by PN mixtures.
Fat emulsions are know to contain higher concentrations of less active isomers compared with the alpha form. Therefore the study recognised it is important to supplement some PN mixtures with vitamin additives containing alpha tocopherol.
The benefits
- The results of the study contributed to the understanding of vitamin E delivery in all-in-one PN mixtures and the loss or degradation of admixed nutrients.
- These findings will provide nutritional and therapeutic value to patients and ensure correct vitamin levels are administered.
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