Kearney M C, Allwood M C, Martin H, Neal T, Hardy G
Andaris Ltd., Ruddington, Nottingham, United Kingdom.
Nutrition. 1998 Feb;14(2):173-8. doi: 10.1016/s0899-9007(97)00430-9.
This study was undertaken to investigate the stability of ascorbic acid and its primary degradation product, dehydroascorbic acid, in total parenteral nutrition (TPN) mixtures. The influence of the type of bag and the commercial source of amino acid on ascorbate degradation was examined, using a stability-indicating high-pressure liquid chromatography (HPLC) method. Ascorbic acid was most stable in multilayered bags, compared with ethylvinyl acetate (EVA) bags. Results indicated that, in multilayered bags, the initial rapid ascorbic acid degradation was greatest in TPN mixtures containing amino acid infusions without reducing activity. In contrast, degradation in TPN mixtures containing amino acids with reducing compounds (Vamin 14 and Freamine III 8.5%) was less than 10% of the added amount. Dehydroascorbic acid degraded approximately in parallel with ascorbic acid, and it contributed to the total available ascorbate activity. The addition of air to TPN mixtures in multilayered bags caused accelerated degradation of both ascorbic acid and dehydroascorbic acid. It is concluded that TPN mixtures compounded in multilayered bags can be safely assigned extended shelf lives, especially if compounded using an amino acid with reducing activity. This is principally due to the protective effect of the bag wall in preventing oxygen transmission, the cause of ascorbic acid oxidation, because oxygen transmission through the bag wall is minimized during storage. TPN mixtures stored in EVA bags should be administered within 2-4 d of compounding, depending on the amino acid infusion used.
本研究旨在调查全胃肠外营养（TPN）混合液中维生素C及其主要降解产物脱氢维生素C的稳定性。采用稳定性指示高压液相色谱（HPLC）法，研究了袋子类型和氨基酸商业来源对维生素C降解的影响。与乙烯-醋酸乙烯酯（EVA）袋相比，维生素C在多层袋中最稳定。结果表明，在多层袋中，初始快速的维生素C降解在含有无还原活性氨基酸输注液的TPN混合液中最为显著。相反，在含有具有还原化合物（凡命14和乐凡命III 8.5%）的氨基酸的TPN混合液中，降解量小于添加量的10%。脱氢维生素C的降解与维生素C大致平行，并且它对总的可用维生素C活性有贡献。向多层袋中的TPN混合液中通入空气会导致维生素C和脱氢维生素C的加速降解。得出的结论是，在多层袋中配制的TPN混合液可以安全地延长保质期，特别是如果使用具有还原活性的氨基酸进行配制。这主要是由于袋壁在防止氧气透过方面的保护作用，氧气透过是维生素C氧化的原因，因为在储存期间通过袋壁的氧气透过被最小化。储存在EVA袋中的TPN混合液应根据所用的氨基酸输注液在配制后2 - 4天内使用。
