Composition comprising an organic liquid diluent and a cellulose ether of very low viscosity
A liquid composition which comprises an organic liquid diluent and at least one non-ionic cellulose ether having a viscosity of up to 2.33 mPa·s, measured as a 2 wt.-% solution in water at 20° C., is stable over an extended time period. The liquid composition is useful for preparing a solid dispersion comprising at least one active ingredient in at least one cellulose ether by spray-drying. Alternatively a solid dispersion can be produced by blending and extruding at least one active ingredient, at least one cellulose ether having a viscosity of up to 2.33 mPa·s and optionally one or more adjuvants.
1. A process for producing a solid dispersion comprising at least one drug in at least one water-soluble non-ionic cellulose ether having a viscosity of from 1.20 to 2.33 mPas, measured as a 2 wt.-% solution in water at 20° C.,
comprising the steps of providing a solution of at least one drug and at least one water-soluble non-ionic cellulose ether in a liquid diluent and removing liquid diluent from the solution,
wherein said at least one non-ionic water-soluble cellulose ether is a hydroxypropyl methylcellulose having a DS(methyl) of from 1.0 to 2.5 and an MS(hydroxypropyl) of from 0.05 to 0.90 or a methylcellulose having a DS(methyl) of from 1.0 to 2.5 and has a viscosity from 1.20 to 2.33 mPas, measured as a 2 wt.-% solution in water at 20° C., and the liquid diluent is an organic diluent or a diluent comprising at least 75 weight percent of an organic diluent and up to 25 weight percent of water, based on the total weight of organic diluent and water, wherein the organic diluent is selected from the group consisting of alcohols, ethers, ketones, acetates, halogenated hydrocarbons, and nitriles, and
wherein said solution of the at least one drug and the at least one water-soluble non-ionic cellulose ether in the liquid diluent has a viscosity after storage for 16 hours at 25° C. that is not more than 15-fold of the viscosity of the solution at 25° C. 30 minutes after the solution has been prepared when said solution comprises 10 wt. % of the water soluble non-ionic cellulose ether.
2. The process of claim 1 wherein liquid diluent is removed from the solution by spray-drying, by casting the solution into a film or a capsule or by applying the solution onto a solid carrier.
3. The process of claim 1 wherein said drug has an aqueous solubility of 0.5 mg/mL or less.