In order to examine the stability of vitamins in a T P N admixture stored in 3-litre plastic (EVA) bags, two different stability studies were performed. In the first experiment the TPN admixture was stored in darkness at 2-8°C for 96 h and the stability of vitamins determined. The vitamins examined were retinyl palmitate, a-tocopherol, thiamine mononitrate, sodium ascorbate (analysed as reduced ascorbic acid and dehydroascorbic acid), sodium riboflavin-5'-phosphate, pyridoxine hydrochloride, nicotinamide, folic acid, biotin, sodium pantothenate and cyanocobalamin.In the second test the stability of vitamins was determined during simulated infusion from the bag containing the admixture. The vitamins examined were retinyl palmitate, a-tocopherol, sodium riboflavin-5'phosphate and sodium ascorbace (analysed as reduced ascorbic acid and dehydroascorbic acid).The vitamin stability was found to be acceptable for all vitamins except ascorbic acid and folic acid. Total ascorbic acid is the sum of reduced ascorbic acid and dehydroascorbic acid (DHA). It is important to estimate the total ascorbic acid concentration because DHA is also biological active.About 50% of the nominal total ascorbic acid remained after 96 h of storage at 2 4°C in darkness, or after 24 h of simulated infusion initiated immediately after mixing.With folic acid there appears to be assay interference which requires further investigation. I N T R O D U C T I O NTotal parenteral nutrition (TPN) by means of premixed fat, glucose, amino acids, fat-and water-soluble vitamins, trace elements and electolytes in 3-litre plastic bags is now common, The physical and chemical stability of such systems has been extensively evaluated (1,2) and their clinical usefulness has been documented (3).

The stability of the fat-soluble vitamins and thiamine, riboflavin, pyridoxine, ascorbate, and folic acid when administered as part of Intralipid 10% was evaluated. Intravenous pediatric vitamin formulations (Vitalipid N Infant and Soluvit Infant) containing the daily dose for term neonates were diluted with Intralipid to final volumes of 12.5 mL or 260 mL. The volumes were then delivered for 24 hours via dihexylethyl-phthalate-free in vitro infusion systems that simulated clinical conditions. The first vitamin-Intralipid admixture (12.5-mL volumes) was pumped (by syringe) during 24 hours through neonatal infusion sets placed in an incubator (37 +/- 1 degree C, bilirubin light). Aliquots were collected at the beginning of the experiment and after 24 hours of infusion. The second admixture (260-mL volumes) was pumped (by a peristaltic pump) through infusion sets during 24 hours and was exposed to periodic indirect sunlight and to continuous fluorescent light to stimulate the feeding of a child. Aliquots were collected at 0, 8, and 24 hours during administration of the admixtures. The vitamin concentrations were measured by high-performance liquid chromatography. The effect of the vitamins on the stability of the emulsion was also assessed by visual inspection, lipid globule size distribution, and pH change. Losses of vitamins vary from different experimental conditions and were for the fat-soluble vitamins essentially nil, except for phylloquinone, which was 5% to 17% below the initial level. Thiamine, pyridoxine, and folic acid were stable. Losses of riboflavin and ascorbate amounted to 10% to 20% and 9% to 52%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

This work deals with the optimization of the separation between the two isomers of phylloquinone by High Performance Liquid Chromatography regarding resolution, peak separation, retention time and peak height per quantity of sample injected. As an application of the separation method the proportions of cis‐ and trans‐phylloquinone in a fat emulsion for parenteral nutrition, also containing the other fat soluble vitamins A, D2 and E, were determined.

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