Stability studies of parenteral nutrition with a high dose of vitamin C

Postoperative administration of parenteral nutrition has become routine management in patients with gastrointestinal cancer. Providing patient the complete parenteral nutrition containing not only the macronutrients and electrolytes but also adequate doses of vitamins is a significant issue of nutritional therapy. The aim of the study was to develop parenteral nutrition containing a high dose of vitamin C (500 mg) and evaluate their stability.

Five compositions of parenteral nutrition were developed and stored for seven days in three different conditions. Physical stability studies including visual examination and determination of pH, size of lipid droplets (using dynamic laser scattering method), and zeta potential (using laser Doppler electrophoresis method) were performed for all studied parenteral nutrition with and without vitamin C immediately after preparation and after storage. The content of vitamin C was determined using high-performance liquid chromatography (HPLC) method.

The addition of vitamin C to parenteral nutrition did not affect its physical stability. Degradation of vitamin C in parenteral nutrition occurred according to first-order kinetics reaction. The content of vitamin C remained above 90% of zero-time content within the first 24 h for each studied parenteral nutrition compositions stored at 4°C and 25°C with light protection.

Vitamin C added to parenteral nutrition was unstable regardless of the storage conditions nor parenteral nutrition compositions. However, for the first 24 h, the content of vitamin C remained in the pharmacopoeial limit. Therefore, supplementation of parenteral nutrition admixtures with vitamin C in the dose of 500 mg is possible in the condition of administration to the patients within the first 24 h.