title: Physicochemical stability assessments of lipid emulsions of varying oil composition.
abstract: OBJECTIVE
  Intravenous lipid emulsions have been shown to be unstable when the percent fat >5 microm (PFAT >5 microm) exceeds 0.4% by weight of the total fat present. We investigated the physicochemical stability of a standard low amino acid and carbohydrate mixture containing electrolytes when combined with four different commercial intravenous lipid emulsions of varying oil composition.
  
  
  METHODS
  The 20% (w/v) lipid emulsions studied were composed of the following oils (by weight): 1) 1 : 1 soybean/safflower (SS); 2) 100% soybean (S); 3) 1 : 1 soybean/MCT (SM) and 4) 4 : 1 olive/soybean (OS). Physicochemical stability was assessed by light obscuration or extinction using a single-particle optical sensing technique to detect growth of fat globules in the large diameter tail (>1 microm) of the droplet size distribution and by visual analyses for evidence of phase separation.
  
  
  RESULTS
  The physicochemical stability of SS and S-based all-in-one mixtures significantly deteriorated over time when compared to the mixtures made from SM and OS. In addition, of the four mixtures studied that contained SS (n=2) and S (n=2), only one of each bag studied showed visually obvious destabilization by the presence of free oil from phase separation, despite highly abnormal changes in the globule size distribution of all four preparations.
  
  
  CONCLUSIONS
  The results suggest that all-in-one mixtures composed of either soybean oil alone or in combination with safflower oil are less stable than those mixed with either MCT or olive oil which also contain sodium oleate that can act as co-emulsifying agent.
authors.affiliation: Department of Medicine, BI Deaconess Medical Center, Boston, MA, USA.
authors.forename: D F
authors.initials: DF
authors.lastname: Driscoll
authors.forename: K
authors.initials: K
authors.lastname: Giampietro
authors.forename: D P
authors.initials: DP
authors.lastname: Wichelhaus
authors.forename: H
authors.initials: H
authors.lastname: Peterss
authors.forename: J
authors.initials: J
authors.lastname: Nehne
authors.forename: W
authors.initials: W
authors.lastname: Niemann
authors.forename: B R
authors.initials: BR
authors.lastname: Bistrian
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004355:Drug Stability; D005079:Excipients; D005217:Fat Emulsions, Intravenous / Q000737:chemistry*; D005511:Food Handling; D006801:Humans; D019301:Oleic Acid; D000069463:Olive Oil; D010288:Parenteral Nutrition; D010316:Particle Size; D010938:Plant Oils; D012450:Safflower Oil; D013024:Soybean Oil; D013997:Time Factors
chemical_list: D005079:Excipients; D005217:Fat Emulsions, Intravenous; D000069463:Olive Oil; D010938:Plant Oils; D019301:Oleic Acid; C013173:osteum; D013024:Soybean Oil; D012450:Safflower Oil