Solubility total parenteral nutrition solutions

Vitamin analyses in elemental diets are frequently required for process and quality control. Van der Horst et al. developed reversed phase methodology to determine the water-soluble vitamins, including PN, in total parenteral nutrition solutions (103). Iwase described a HPLC method to analyze the aqueous extract from an elemental pediatric diet for PN and nicotinamide (104). Chromatography involved a two-column, double-UV detector system to allow simultaneous determination of both PN and nicotinamide (104). 

A van der Horst, HJM Martens, PNFC de Goede. Analysis of water-soluble vitamins in total parenteral nutrition solution by high pressure liquid chromatography. Pharm Week Sci 11 169-174, 1989. 

Additionally, sodium bicarbonate is used in solutions as a buffering agent for erythromycin, lidocaine, local anesthetic solutions, and total parenteral nutrition (TPN) solutions. In some parenteral formulations, e.g., niacin, sodium bicarbonate is used to produce a sodium salt of the active ingredient that has enhanced solubility. Sodium bicarbonate has also been used as a freeze-drying stabilizer and in toothpastes. 

The solubility of calcium and phosphate in total parenteral nutrition (TPN) solutions is dependent on the pH of the solution. TPN solutions are, of course, clinically acceptable only when precipitation can be guaranteed not to occur. Dibasic calcium phosphate, for example, is soluble only to the extent of 0.3 g dm whereas monobasic calcium phosphate has a solubility of 18 g dm . At low pH the monobasic form predominates, while at higher pH values the dibasic form becomes available to bind with calcium and precipitates tend to form. ... 

In summary Because of the short time required to develop biochemical evidence of a deficiency of many water soluble vitamins, it would appear that these nutrients should be included from the initiation of any complete parenteral nutrition program. If MVI (USV Pharm.) is used, care should be taken to insure that the patient does not receive excessive amounts of the fat soluble vitamins. Ideally there should be separate preparations of the water and fat soluble vitamins. Unless these solutions are made available for study, the actual requirement for each vitamin will remain difficult to assess. In this regard, it is quite disturbing that recently the FDA, with disregard for the needs of the patients whose lives may be saved by total parenteral nutrition, has placed severe restrictions on the use of intravenous vitamin preparations. 

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