Method for galenically preparing a therapeutic composition based on aspirin

A method for preparing a therapeutical composition for internal use, in galenic presentation, and containing at least one active principle of slightly or non-hydrosoluble nature in solid form within a substrate of cross linked structure, especially an edible carbohydrate, the active product being distributed therein in the state of finely dispersed microcrystals, and the method comprising the steps of:

• (a) preparing an organic solvent of the said active principle and an adjuvant constituted by a hydrocolloidal organic polymer having hydrophilic properties, said polymer being soluble in said solvent and in a solid state at ambient temperature;
• (b) incorporating and dissolving said adjuvant in said solvent within a percentage ranging from 10 percent to 60 percent of the total weight of the solvent, at a temperature ranging from 30.degree. C. at the beginning of the dissolution to 18.degree. C. at the end of the dissolution;
• (c) dissolving the said active principle in said solvent to obtain a solution of both adjuvant and active principle within said solvent, on the basis of substantially one part of active product for between 6 and 8 parts of the solution formed by the solvent and the adjuvant in solution therein;
• (d) impregnating the thus obtained solution on a substrate of cross linked structure constituted by an edible carbohydrate until the solution is homogeneously absorbed within the substrate, said impregnation being conducted at a temperature of the edible carbohydrate ranging from 25.degree. C. to 35.degree. C. and under reduced pressure of substantially 700 mbar;
• (e) evaporating by drying in vacuo at ambient temperature the solvent from the solution within the substrate in order to obtain simultaneous deposition of microcrystals of active principle and of the adjuvant in solid state, within the cross linked structure of the substrate, the solidification of the adjuvant forming a protective coating for said individual microcrystals, and thus limiting the crystalline spread and the size of the microcrystals, which size is limited to 10 .mu. or less, while binding and cementing them and thus avoiding their entrainment by eluation during evaporation;
• (f) repeating a cycle including steps (d) and (e) until a predetermined proportion of the microcrystals of active principle with hydrocolloidal coating is absorbed and finely dispersed within the substrate;
• and
• (g) submitting the said substrate to compression in an ambiance of controlled hygrometry of substantially 20 percent to form tablets, granules or pills, within which each individual microcrystal is coated by hydrocolloidal polymer forming an hydrophilic matrix ensuring during compression and after administration, especially per os, physical and chemical protection of each individual microcrystal of said active agent, thus avoiding direct aggressive and stagnant contact of the microcrystals of active agent with the mucous membrane and an unpleasant taste, the said hydrocolloidal polymer furthermore ensuring regular dissolution of the microcrystals within the hydrophilic matrix impregnated by biologic liquid such as saliva and subsequent absorption in soluted state within the body.