GB1249558A — Process for the preparation of size-controlled colloidal iron sols and their stabilized solutions

USPTO Abstract

1,249,558. Ferric hydroxide sols. AMERICAN CYANAMID CO. 19 Aug., 1969, No. 41292/69. Heading ClA. [Also in Division A5] Ferric hydroxide sols for intramuscular injection, containing at least 1% Fe and having a viscosity not greater than 30 centistokes, are prepared by reacting an aq. solution of a ferric salt (containing 11-40% of the Fe required in the product) with sufficient weak base ionexchange resin in the OH- form to exchange all the anions of the salt, continuing the reaction until the pH is from 2-4, filtering, adding more ferric salt and resin and maintaining the pH at from 1À6-4, filtering again and adding yellow potato starch dextrin solution having an intrinsic viscosity of from 0À06-0À16 such that the ratio of dextrin : Fe is from 1À3 : 1 to 3À2 : 1, adjusting the pH to from 6 to 8, and adjusting the water content if necessary. The preferred iron salt is ferric chloride hexahydrate and the preferred product should contain about 10% Fe.