Patent GB-825936-A (GB)
Title: Improvements in and relating to soybean phosphatide emulsifiers
Inventor: DAILEY JOSEPH PATRICK
IPC: A61K9/00
Filed: 1956-02-09
Abstract: The invention comprises a stabilized soya bean phosphatide emulsifier having an iodine number of from 30 to 60 and a cloud point of not more than 60 DEG  C.  The product may be obtained by contacting a mixture of soya bean phosphatides containing catalyst poisons with a solvent mixture containing at least one non-polar solvent in which the phosphatide mixture containing catalyst poisons is substantially soluble and at least one non-aqueous inert polar solvent in which the phosphatide mixture is of limited solubility and the catalyst poisons are substantially insoluble, regulating the relative proportions of the polar and non-polar solvents such as to selectively solubilize substantially all of the phosphatides in the solvent mixture or in the polar solvent rich phase of the mixture, separating the phosphatides substantially free of catalyst poisons and hydrogenating the purified phosphatides to an iodine value of from 30 to 60, the product having a cloud point of not more than 60 DEG  C.  The non-polar solvent is preferably a hydrocarbon, such as cyclohexane, methyl cyclohexane, petroleum ether, or a petroleum hydrocarbon fraction, e.g.  Skelly-Solve, and the polar solvent may be methanol, ehtanol, isopropanol, butanol, or dioxane.  The solution of the crude phosphatide in the non-polar solvent is preferably filtered before adding the polar solvent, a bacterial filter being preferably employed.  The hydrogenation of the purified phosphatide is suitably effected catalytically at 20 DEG  to 150 DEG  C. and at a pressure of 16 to 2500 p.s.i.  Specified hydrogenation catalysts are Raney nickel, platinum oxide or palladium on charcoal.  The volume of hydrogen gas required to give a product of the specified iodine number range of 30 DEG  to 60 DEG  C. can vary within the range of about 15 to 42 c.c. per gram of purified phosphatide material when the hydrogenation is carried out at about 23 DEG  C. and at about atmospheric pressure.  The term "cloud point" is defined as the temperature in degrees C. of a refined coconut oil solution containing 16.67% by weight of the soya bean phosphatide material at which a perceptible cloud of insoluble matter is formed.  In a typical example commercial lecithin is dissolved in cyclohexane, methanol is added to the resulting solution and the solution agitated and then allowed to settle.  The supernatant phase is then separated by decantation, clarified by filtration through a filter pad under pressure, concentrated by evaporation under reduced pressure and the concentrate is then catalytically hydrogenated to give a product having an iodine value and cloud point within the specified range. In another example the supernatant phase after decantation as above is evaporated to dryness under reduced pressure and the dry powder is dissolved in cyclohexane, isopropanol is added and the resulting mixture catalytically hydrogenated.  The emulsifier product may be combined with water and a pharmaceutical fat to form an oil-in-water emulsion suitable for parenteral administration (see Group III).ALSO:An oil-in-water emulsion suitable for parenteral administration comprises a stabilized soya bean phosphatide emulsifier having an iodine number of from 30 to 60 and having a cloud point of not more than 60 DEG  C. (see Group IV (b)) combined with water and a pharmaceutical fat, such as refined edible coconut oil.  A metabolizable carbohydrate, e.g. glucose, and an antioxidant such as alpha-tocopherol may also be included in the emulsion.