Vitamin Stability in a TPN Mixture Stored in an Eva Plastic Bag

Abstract

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).

Physical characteristics of total parenteral nutrition bags significantly affect the stability of vitamins C and B1: a controlled prospective study

“…8,11,16 Our results confirm that important ascorbate losses occur just after TPN compounding. The residual oxygen in the TPN mixture is assumed to cause a 30-to 50-mg loss of ascorbic acid within the first 6 hours after compounding.…”

“…The halflife of ascorbic acid has been reported as 2 to 52 hours. 4,5,8 -10 Similarly, some investigators have suggested that retinol is not affected by daylight in "allin-one" TPN mixtures, 11 whereas others have observed a 90% degradation. 1 Contradictory results have also been reported for tocopherol, which has been shown to be stable 12 or degraded 13 in daylight.…”

Losses of vitamin A and E in parenteral nutrition suitable for premature infants

“…In studies using a lipid soluble preparation with retinylpalmitate and a-tocopherol, the concentrations of retinylpalmitate delivered after 24 h were 50 -100% (Drott et al, 1991;Dahl et al, 1986Dahl et al, , 1994, which are comparable to our results of 76 -94%. The reported final a-tocopherol concentrations after 24 h were in the range of 70 -105% of the intended doses (Drott et al, 1991;Dahl et al, 1986Dahl et al, , 1994.…”

“…The reported final a-tocopherol concentrations after 24 h were in the range of 70 -105% of the intended doses (Drott et al, 1991;Dahl et al, 1986Dahl et al, , 1994. Again, the concentrations we measured (85 -94%) were within this range.…”

“…Data on the delivery of vitamins A and E during total parenteral nutrition in adults and infants have been reported (Drott et al, 1991;Gillis et al, 1983;Greene et al, 1987;Gutcher et al, 1984;Henton et al, 1990;Riggle & Brandt, 1986;Shenai et al, 1981Shenai et al, , 1982Thomas et al, 1991;Allwood & Plane, 1986;Dahl et al, 1986Dahl et al, , 1994, but only one study investigated the supply of these two vitamins to premature infants under the particular conditions of a neonatal intensive care unit (Inder et al, 1995). Variation of experimental conditions such as the use of different tubing materials, humidity and the elevated temperature in an incubator may substantially influence the delivery of vitamins A and E to the recipient infant (Autian, 1963).…”