Patent GB-422948-A (GB)
Title: Method of producing therapeutically and disinfectantly active substances
IPC: C02F1/50
Filed: 1934-05-14
Abstract: Colloidal solutions are prepared by reacting compounds yielding silver ions with compounds of polyvalent metals, for example manganese, cobalt, iron and cerium, in an alkaline medium, and in the presence of protective colloids such as albuminous substances, vegetable mucilage, or lecithins.  The alkalinity may be produced by addition of alkalis, ammonia, or carbonates, or by the use of oxides, hydroxides, or basic salts of silver or the other reacting metals. The products consist of finely divided silver together with the higher oxides or hydroxides of the polyvalent metals.  The quantity of the reaction products can be pre-determined by use of a known quantity of alkaline-reacting substance.  In an example, a solution of silver and manganese nitrates is added to an aqueous solution of gelatine.  Caustic soda is stirred in, the colloidal solution dialyzed with water until the dialysate is neutral and, if necessary, filtered.ALSO:Therapeutic and disinfectant products are prepared by reacting compounds yielding silver ions with compounds of polyvalent metals, for example manganese, cobalt, iron, and cerium, in an alkaline medium.  The alkalinity may be produced by addition of alkalis, ammonia, or carbonates, or by the use of oxides, hydroxides, or basic salts of silver or the other reacting metals. The products consist of finely divided silver together with the higher oxides or hydroxides of the polyvalent metals.  They may be deposited during their evolution upon carriers such as textile fibres, cotton, or fabric to give sterile dressings, or upon animal charcoal, silica gel, or bole, which may first be treated with alkaline substances, or upon alkaline-reacting substances such as alkaline-earth carbonates and magnesium or zinc oxide, if desired in the presence of other therapeutic substances.  The reaction may proceed in the presence of protective colloids such as albuminous substances, vegetable mucilage or lecithins to give colloidal solutions or fine suspensions used for the treatment of gonorrhoea or other infectious diseases.  The products may be treated to remove the oxides and leave silver in an active form; for example, manganese dioxide is dissolved out with acidified hydrogen peroxide.  The quantity of the reaction products can be pre-determined by use of a known quantity of alkaline-reacting substance; thus, a fibrous or other carrier is impregnated with a measured quantity of alkali and then treated with a solution of excess silver nitrate and manganous sulphate.  The products are used for sterilizing and preserving liquids such as fruit juices and water.  The liquids can be caused to flow over a filter of the products preferably deposited on a porous carrier, or storage vessels and containers can be impregnated on their inner walls, or fitted with impregnated liners.  Packing material such as wood-wool, sawdust, or coke meal together with the products can be used for storage of such goods as fruit.  According to examples: (1) A solution of silver nitrate and manganese nitrate is made alkaline with caustic soda.  The precipitate is washed and dried at 100 DEG C.  (2) Sodium silicate solution is added to a solution of silver and manganese nitrates. After heating on the water-bath, the precipitate is drawn off, washed, and dried at 100-110 DEG  C.  The product has a silver content of 10 per cent.  (3) Gauze is dipped in a solution of silver and manganese nitrates, pressed, placed in normal caustic soda solution, washed, and dried.  (4) To a solution of gelatine in water, a solution of silver and manganese nitrates is added. Caustic soda is stirred in, the colloidal solution dialyzed with water until the dialysate is neutral and, if necessary, filtered.ALSO:Products used for sterilizing and preserving liquids, e.g water, are prepared by reacting compounds yielding silver ions with compounds of polyvalent metals, for example, manganese, cobalt, iron, and cerium, in an alkaline medium.  The alkalinity may be produced by addition of alkalis, ammonia, or carbonates, or by the use of oxides, hydroxides, or basic salts of silver or the other reacting metals.  The products consist of finely divided silver together with the higher oxides or hydroxides of the polyvalent metals.  They may be deposited during their evolution upon carriers such as textile fibres, cotton, or fabric, or upon animal charcoal, silica gel, or bole, which may first be treated with alkaline substances, or upon alkaline-reacting substances such as alkaline-earth carbonates and magnesium or zinc oxide. The reaction may proceed in the presence of protective colloids such as albuminous substances, vegetable mucilage or lecithins to give colloidal solutions or fine suspensions.  The products may be treated to remove the oxides and leave silver in an active form; for example, manganese dioxide is dissolved out with acidified hydrogen peroxide.  The quantity of the reaction products can be predetermined by use of a known quantity of alkaline-reacting substance; thus, a fibrous or other carrier is impregnated with a measured quantity of alkali and then treated with a solution of excess silver nitrate and manganous sulphate.  The liquids to be treated can be caused to flow over a filter of the products preferably deposited on a porous carrier, or storage vessels and containers can be impregnated on their inner walls or fitted with impregnated liners.  According to examples: (1) A solution of silver nitrate and manganese nitrate is made alkaline with caustic soda. The precipitate is washed and dried at 100 DEG  C.  (2) Sodium silicate solution is added to a solution of silver and manganese nitrates.  After heating on the water-bath, the precipitate is drawn off, washed, and dried at 100-110 DEG  C.  The product has a silver content of 10 per cent.  (3) Gauze is dipped in a solution of silver and manganese nitrates, pressed, placed in normal caustic soda solution, washed, and dried.  (4) To a solution of gelatine in water, a solution of silver and manganese nitrates is added.  Caustic soda is stirred in, the colloidal solution dialyzed with water until the dialysate is neutral and, if necessary, filtered.