Propofol

Abstract

Propofol an alkylphenol (usually referred to as a hindered phenol) with anaesthetic properties, is virtually insoluble in water. It was originally solubilized in Cremophor EL but the association of this solubilizing agent and anaphylactic reactions led to its withdrawal, and the currently available preparation is a 1% w/v aqueous emulsion containing 10% w/v soya bean oil, 1.2% w/v egg phosphatide and 2.25% w/v glycerol. (This is similar to the commercially available fat emulsion, Intralipid.). The pH is 6-8.5 and the pK(a) of the drug in water is 11. This review deals with the emulsion preparation that is free from the anaphylactic responses of the original formulation. It contains 10 mg m--1, is free flowing and is as easy to inject as an aqueous solution. It is made isotonic with glycerol and is sealed under nitrogen. Precautions that apply to intravenous fat emulsions must be taken with propofol, which should be stored below 25°C but must not be frozen. The ampoules should be shaken before use. Filters should not be used during administration and the emulsion should not normally be mixed with other therapeutic agents or infusion fluids, with the exception of dextrose 5%. It can be administered into a crystalloid infusion through a Y-piece close to the injection site.