Preparation of colloidal aqueous solutions of active substances of low solubility
AssigneeKnoll Aktiengesellscahft
InventorsJoerg Rosenberg, Cynthia Romerdahl, Juergen Heberger
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Abstract
A process with whose aid active substances of low solubility can be processed together with phospholipids to give a homogeneous solution, which comprises a) mixing the active substance with a phospholipid, b) adding an acidic aqueous solution of a carbohydrate to the residue at elevated temperature, and stirring this mixture at elevated temperature until a homogeneous colloidal solution is produced, and c) cooling the solution, and adjusting to a pH of 4-5 and sterilizing is described.
Claims4
A process for the production of unaggregated homogeneous emulsions of basic active substances having nitrogen atoms protonatable in acids and in ionic form at acidic pH, with phospholipids which comprises
- a) creating a mixture comprising an active substance and a phospholipid by dissolving the active substance and the phospholipid in an organic solvent and then removing the solvent;
- or by mixing the active substance and the phospholipid without a solvent, and then
- b) adding an acidic aqueous solution of a carbohydrate to the mixture at an elevated temperature, and stirring this mixture at said temperature until a homogeneous colloidal emulsion is produced;
- and then
- c) cooling the emulsion, adjusting to pH 4-5;
- wherein said pH-adjusted emulsion is able to pass through a filter having a pore size of 0.2 .mu.m.
Dependencies are inferred from the claim text.