Patent GB-653341-A (GB)
Title: An improved alginate medical or surgical preparation
IPC: A61L15/28
Filed: 1948-04-27
Abstract: Fibres or gauze of a double alginate of a water-solubilizing and water-insolubilizing base are prepared by replacing all the H ions of alginic acid by solubilizing and insolubilizing ions in a random manner and in such proportions that the composition so formed can swell to any desired degree in watery fluids but cannot disperse.  A water-insoluble alginate such as calcium alginate gauze, may be leached with acid, e.g. hydrochloric or acetic to remove all positive ions, immersed in a water-miscible vehicle such as ethyl alcohol and a known amount of CaCl2 or calcium acetate added.  The alcoholized gauze is then neutralized with sodium hydroxide to produce a calcium-sodium alginate of known composition.  Alternatively, the calcium alginate gauze may be leached with sufficient acid to leave a predetermined residual calcium content and the gauze so treated then neutralized with sodium hydroxide.  Zinc ions may be used instead of calcium, and potassium ammonium or magnesium in place of the sodium ions.ALSO:A double alginate of a water-solubilizing and water-insolubilizing base is prepared by replacing all the hydrogen ions of alginic acid by solubilizing and insolubilizing ions in a random manner and in such proportions that the composition so formed can swell to any desired degree in watery fluids but cannot disperse. A water-insoluble alginate such as calcium alginate gauze, may be leached with acid, e.g. hydrochloric or acetic to remove all positive ions, immersed in a water-miscible vehicle such as ethyl alcohol and a known amount of calcium chlorides or calcium acetate added.  The alcoholized gauze is then neutralized with sodium hydroxide to produce a calcium-sodium alginate of known composition. Alternatively, the calcium alginate gauze may be leached with sufficient acid to leave a pre-determined residual calcium content and the gauze so treated then neutralized with sodium hydroxide. Zinc ions may be used instead of calcium, and potassium, ammonium or magnesium in place of sodium ions.ALSO:A coherent medical or surgical preparation consisting of a double alginate of a water-solubilizing and water insolubilizing base is prepared by replacing the H-ions of alginic acid by solubilizing and insolubilizing ions in a random manner and in such proportions that the composition so formed can swell to any desired degree in watery fluids but cannot disperse.  A water-insoluble alginate such as calcium alginate gauze, may be backed with acid, e.g. hydrochloric or acetic to remove all positive ions, immersed in a water miscible vehicle such as ethyl alcohol and a known amount of calcium chloride or acetate added. The alcoholized gauze is then neutralized with sodium hydroxide to produce a calcium/sodium alginate of known composition. Alternatively, the calcium alginate gauze may be backed with sufficient acid to leave a predetermined residual calcium percentage and the gauze so treated neutralized as before with sodium hydroxide.  Any water-insoluble alginate such as zinc may be used in place of the calcium alginate and potassium ammonium or magnesium, may be used in place of the sodium alginate.  As the solubilities of the mixtures vary with the relative proportions of the soluble to insoluble alginates in the mixture, it is possible to prepare a series of products of graded solubilities in the body fluids.  Anti-biotics, chemotherapeutics and antiseptic may be incorporated in the preparations.