1. A pharmaceutical composition comprising an open matrix network containing a pharmaceutically active ingredient, wherein the open matrix network contains inulin. A pharmaceutical composition comprising a matrix containing a pharmaceutically active ingredient, wherein the matrix rapidly disintegrates upon contact with an aqueous solution or saliva, and wherein said matrix contains inulin. 3. The pharmaceutical composition according to claim 1 or 2, wherein inulin is the main matrix forming agent. The pharmaceutical composition according to claim 1 or 2, where the matrix contains inulin and mannitol. The pharmaceutical composition according to claim 1 or 2, wherein the matrix comprises inulin and trehalose. The pharmaceutical composition according to claim 1 or 2, wherein the matrix contains inulin and raffinose. The pharmaceutical composition according to claim 1 or 2, wherein at least 80% of said composition is dissolved in an aqueous medium or in saliva within 10 seconds. The pharmaceutical composition according to claim 1 or 2 in an oral dosage form. The pharmaceutical composition of claim 8, adapted for sublingual administration. The pharmaceutical composition according to claim 1 or 2, obtained by sublimation of the solvent from a liquid preparation containing the active ingredient and inulin in the solvent. The pharmaceutical composition of claim 10, wherein the sublimation is carried out by freeze-drying the preparation. The pharmaceutical composition according to claim 1 or 2, wherein the active ingredient is desmopressin acetate. The pharmaceutical composition according to claim 1 or 2, wherein the active ingredient is loratidine. The pharmaceutical composition according to claim 1 or 2, wherein the active ingredient is famotidine. The pharmaceutical composition according to claim 1 or 2, g1. Фармацевтическая композиция, содержащая открытую матричную сеть, несущую фармацевтически активный ингредиент, где открытая матричная сеть содержит инулин.2. Фармацевт