FREMGANGSM}TE TIL FREMSTILLING AV MEGET L¦SELIG GAFREMGANGSMAATE TIL FREMSTILLING AV MEGET LOESELIG MMAGLOBULIN GAMMAGLOBULIN

1435816 Obtaining gamma globulin BAXTER LABORATORIES INC 26 Nov 1973 [27 Nov 1972] 54703/73 Heading A5B A water-soluble, intravenously administrable y-globulin is prepared by suspending whole plasma or any of Cohn Plasma Fractions II, II+III and III in normal physiological saline, adjusting the pH to 6.5 to 7.5, mixing the suspension with calcium phosphate to absorb coagulation factors, removing the precipitate and subjecting the supernatant to three successive precipitations by addition of a watersoluble block copolymer of ethylene oxide and propylene oxide comprising at least 50% ethylene oxide and having a polyoxypropylene hydrophobic base molecular weight of at least 950, the first at a pH of 4 to 5 with a final concentration of 6 to 8.5% block copolymer; the second at a pH of 4.5 to 5.5 and a final concentration 8.5% to 10%, and the third at a pH of 6.5 to 7.5 and a final concentration of 14 to 16%, the supernatant from the first two precipitations being retained and the third precipitate being the required product. If whole plasma Cohn Fraction II+III are used, the starting material is preferably subjected to an initial precipitation step at pH 6.5 to 7.5 to a concentration of 12 to 16% to remove albumin which remains in the supernatant whilst the globulins are precipitated.