Analysis of lipid globules in parenteral neonatal nutrition

Parenteral nutrition bypasses the digestive tract and injects prepared nutritional solutions directly into the vein. Doctors prescribe this type of nutrition only to seriously ill individuals when there is no other option. In the case of newborns, parenteral nutrition is hypercritical but essential for survival.

The Faculty of Pharmacy of the Federal University of Rio de Janeiro (Universidade Federal do Rio de Janeiro) conducts research in the field of parenteral nutrition. In a study, the research department wanted to determine whether added trace elements and vitamins affect the physicochemical stability of parenteral nutrition preparations for newborns. The main parameter that is considered equivalent to physicochemical stability is the size of the lipid globules and their percentage in the nutrient preparation. It is essential to know the particle size distribution of fat globules in parenteral neonatal nutrition, since a fat globule that is too large can promote coalescence, making it impossible for the human body to absorb them parenterally. An unstable particle size distribution is potentially dangerous for the patient.

The lipid globules of three different parenteral neonatal nutrition preparations were analyzed. All three samples contained the basic ingredients with three different compositions: a first one contained the vitamins, a second one the trace elements and a third one both the vitamins and the trace elements.

Until now, there is no defined specific scientific standard for the analysis of lipid globules in parenteral neonatal nutrition. The research team from the University of Rio de Janeiro therefore referred to the existing pharmacopoeia USP 729 (Globule Size Distribution in Lipid Injectable Emulsions) and USP 788 (Particulate Matter in Injections). Both pharmacopoeias recommend the Light Extinction method for the analysis of injectables.

For the Light Extinction method, the laboratory particle counter, the PAMAS SVSS, was used. A PAMAS HCB-LD-50/50 light blocking sensor was integrated into the system. The PAMAS USP software program records the measurement results for data analysis.

According to USP 729, the fat percentage in parenteral neonatal nutrition should not exceed 0.05%. Or more precisely, the lipid injectable emulsion should not contain more than 0.05% fat globules larger than 5 µm. Fat globules larger than 5 µm are dangerous and therefore interesting to monitor for pharmaceutical applications, because fat globules of this size can obstruct the lungs, cause pulmonary embolism or be fatal if ingested parenterally and in excessive quantities.

Using the PAMAS SVSS, scientists from the University of Rio de Janeiro were able to successfully, accurately and reliably establish that the stability of parenteral neonatal nutrition is not affected by additional vitamins and trace elements. Added vitamins and trace elements do not have a noticeable effect on the distribution of fat globules in injectable emulsions.

bibliography:

Bianca Lobo et al.: Influence of the relative composition of trace elements and vitamins in physicochemical stability of total parenteral nutrition formulations for neonatal use. Nutrition Journal, 2012, 11:26.

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