The currently available preparation is 1% propofol, 10% soybean oil, and 1.2% purified egg phospholipid as an emulsifier, with 2.25%  glycerol as a tonicity-adjusting agent, and sodium hydroxide to adjust the pH. Diprivan contains EDTA, a common chelation agent, that also acts alone (bacteriostatically against some bacteria) and synergistically with some other antimicrobial agents. Newer generic formulations contain sodium metabisulfite or benzyl alcohol as antimicrobial agents. Propofol emulsion is a highly opaque white fluid due to the scattering of light from the tiny (about 150-nm) oil droplets it contains: Tyndall Effect. Developments
A water-soluble prodrug form, fospropofol, has been developed and tested with positive results. Fospropofol is rapidly broken down by the enzyme alkaline phosphatase to form propofol. Marketed as Lusedra, this formulation may not produce the pain at injection site that often occurs with the conventional form of the drug. The U.S. Food and Drug Administration (FDA) approved the product in 2008. However fospropofol is a Schedule IV controlled substance with the DEA ACSCN of 2138 in the United States unlike propofol.By incorporation of an azobenzene unit, a photoswitchable version of propofol (AP2) was developed in 2012, that allows for optical control of GABAA receptors with light. In 2013, a propofol binding site on mammalian GABAA receptors has been identified by photolabeling using a diazirine derivative. Additionally, it was shown that the hyaluronan polymer present in the synovia can be protected from free-radical depolymerization by propofol. References
External links

"Propofol". Drug Information Portal. U.S. National Library of Medicine.
GB patent 1472793, John B Glen & Roger James, "Pharmaceutical Compositions", published 1977-05-04,  assigned to Imperial Chemical Industries Ltd