Novel esterified cellulose ethers of very high molecular weight

Abstract

Esterified cellulose ethers which comprise (i) groups of the formula —C(O)—R—COOA or (ii) a combination of aliphatic monovalent acyl groups and groups of the formula —C(O)—R—COOA, wherein R is a divalent aliphatic or aromatic hydrocarbon group and A is hydrogen or a cation, which have a viscosity of up 50 mPa·s, measured as a 10 wt % solution of the esterified cellulose ether in acetone at 20° C., and a weight average molecular weight M w of at least 220,000 Dalton, or which have a viscosity of up 100 mPa·s, measured as a 10 wt % solution of the esterified cellulose ether in acetone at 20° C., and a weight average molecular weight M w of at least 310,000 Dalton are useful for preparing solid dispersions comprising drugs.

1 . A hydroxypropyl methyl cellulose acetate succinate
 having a DS(methoxyl) of from 1.6 to 2.05,   having a viscosity of up to 50 mPa·s, measured as a 10 wt. % solution of the hydroxypropyl methyl cellulose acetate succinate in acetone at 20° C., and   having a weight average molecular weight M w  of at least 220.000 Dalton,   wherein the hydroxypropyl methyl cellulose acetate succinate has been produced by reacting a hydroxypropyl methyl cellulose having a DS(methoxyl) of from 1.6 to 2.05 with acetic anhydride and succinic anhydride in an aliphatic carboxylic acid as a reaction diluent at a molar ratio of aliphatic carboxylic acid to succinic anhydride of up to 12/1.   
     
     
         2 . The hydroxypropyl methyl cellulose acetate succinate of  claim 1  having a weight average molecular weight M w  of at least 250,000 Dalton. 
     
     
         3 . The hydroxypropyl methyl cellulose acetate succinate of  claim 1  having a viscosity of up 40 mPa·s, measured as a 10 wt. % solution of the hydroxypropyl methyl cellulose acetate succinate in acetone at 20° C. 
     
     
         4 . The hydroxypropyl methyl cellulose acetate succinate of  claim 1  having a DS(methoxyl) of from 1.7 to 2.05. 
     
     
         5 . A composition comprising a liquid diluent and at least one hydroxypropyl methyl cellulose acetate succinate of  claim 1 . 
     
     
         6 . The composition of  claim 5  comprising from 5 to 20 percent of at least one hydroxypropyl methyl cellulose acetate succinate, from 65 to 94 percent of a liquid diluent, and from 1 to 15 percent of an active ingredient, based on the total weight of the composition. 
     
     
         7 . A solid dispersion comprising at least one active ingredient and at least one hydroxypropyl methyl cellulose acetate succinate of  claim 1 . 
     
     
         8 . A dosage form being coated with at least one hydroxypropyl methyl cellulose acetate succinate of  claim 1 . 
     
     
         9 . A capsule shell comprising at least one hydroxypropyl methyl cellulose acetate succinate of  claim 1 . 
     
     
         10 . A hydroxypropyl methyl cellulose acetate succinate having a DS(methoxyl) of from 1.6 to 2.05,
 having a viscosity of up to 100 mPa·s, measured as a 10 wt. % solution of the hydroxypropyl methyl cellulose acetate succinate in acetone at 20° C., and   having a weight average molecular weight M w  of at least 310,000 Dalton,   wherein the hydroxypropyl methyl cellulose acetate succinate has been produced by reacting a hydroxypropyl methyl cellulose having a DS(methoxyl) of from 1.6 to 2.05 with acetic anhydride and succinic anhydride in an aliphatic carboxylic acid as a reaction diluent at a molar ratio of aliphatic carboxylic acid to succinic anhydride of up to 12/1.   
     
     
         11 . The hydroxypropyl methyl cellulose acetate of  claim 10  having a weight average molecular weight M w  of at least 350,000 Dalton. 
     
     
         12 . The hydroxypropyl methyl cellulose acetate of  claim 10  having a viscosity of up 80 mPa·s, measured as a 10 wt % solution of the hydroxypropyl methyl cellulose acetate succinate in acetone at 20° C. 
     
     
         13 . The hydroxypropyl methyl cellulose acetate succinate of  claim 10  having a DS(methoxyl) of from 1.7 to 2.05. 
     
     
         14 . A composition comprising a liquid diluent and at least one hydroxypropyl methyl cellulose acetate succinate of  claim 10 . 
     
     
         15 . The composition of  claim 14  comprising from 5 to 20 percent of at least one hydroxypropyl methyl cellulose acetate succinate, from 65 to 94 percent of a liquid diluent, and from 1 to 15 percent of an active ingredient, based on the total weight of the composition. 
     
     
         16 . A solid dispersion comprising at least one active ingredient and at least one hydroxypropyl methyl cellulose acetate succinate of  claim 10 . 
     
     
         17 . A dosage form being coated with at least one hydroxypropyl methyl cellulose acetate succinate of  claim 10 . 
     
     
         18 . A capsule shell comprising at least one hydroxypropyl methyl cellulose acetate succinate of  claim 10 .