na+150 meq155 meq80 meq k+80 meq80 meq40 meq ca2+360 mg360 mg180 mg mg2+240 mg240 mg120 mg acetate72 meq226 meq134 meq cl−143 meq145 meq70 meq p310 mg465 mg233 mg mvi-1210 ml10 ml10 ml trace elements5 ml5 ml5 ml components prepared solutions prepared solutions generally consist of water and electrolytes; glucose, amino acids, and lipids; essential vitamins, minerals and trace elements are added or given separately. previously lipid emulsions were given separately but it is becoming more common for a "three-in-one" solution of glucose, proteins, and lipids to be administered. added components individual nutrient components may be added to more precisely adjust the body contents of it. that individual nutrient may, if possible, be infused individually, or it may be injected into a bag of nutrient solution or intravenous fluids (volume expander solution) that is given to the patient. administration of individual components may be more hazardous than administration of pre-mixed solutions such as those used in total parenteral nutrition, because the latter are generally already balanced in regard to e.g. osmolarity and ability to infuse peripherally. incorrect iv administration of concentrated potassium can be lethal, but this is not a danger if the potassium is mixed in tpn solution and diluted. vitamins may be added to a bulk premixed nutrient immediately before administration, since the additional vitamins can promote spoilage of stored product. vitamins can be added in two doses, one fat-soluble, the other water-soluble. there are also single-dose preparations with both fat- and water-soluble vitamins such as cernevit. minerals and trace elements for parenteral nutrition are available in prepared mixtures, such as addaven. these additional components in parenteral nutritions, however were subject to stability checks, since they greatly affect the stability of lipid emulsions that serve as the base for these formulations. studies have shown differences in physical and chemical stabilities of these total parenteral nutrition solutions, which greatly influences pharmaceutical manufacturing of these admixtures. emulsifier only a limited number of emulsifiers are commonly regarded as safe to use for parenteral administration, of which the most important is lecithin. lecithin can be biodegraded and metabolized, since it is an integral part of biological membranes, making it virtually non-toxic. other emulsifiers can only be excreted via the kidneys, creating a toxic load. the emulsifier of choice for most fat emulsions used for parenteral nutrition is a highly purified egg lecithin, due to its low toxicity and complete integration with cell membranes. use of egg-derived emulsifiers is not recommended for people with an egg allergy due to the risk of reaction. in situations where there is no suitable emulsifying agent for a person at risk of developing essential fatty acid deficiency, cooking oils may be spread upon large portions of available skin for supplementation by transdermal absorption. another type of fat emulsion omegaven is being used experimentally within the us primarily in the pediatric population. it is made of fish oil instead of the soybean oil based formulas more widely in use. research has shown use of omegaven may reverse and prevent liver disease and cholestasis. history developed in the 1960s by dr. stanley dudrick, who as a surgical resident in the university of pennsylvania, working in the basic science laboratory of dr. jonathan rhoads, was the first to successfully nourish initially beagle puppies and subsequently newborn babies with catastrophic gastrointestinal malignancies. dr. dudrick collaborated with dr. willmore and dr. vars to complete the work necessary to make this nutritional technique safe and successful. in 2019 the uk experienced a severe shortage of tpn bags due to safety restrictions at the sole manufacturing site, operated by calea. the national health service described the situation as an emergency.