Abstract: Two or more esters of a cellulose ether, each having the same ether and ester substituents but different weight average molecular weights are prepared in a process which comprises the steps of esterifying a cellulose ether with (i) an aliphatic monocarboxylic acid anhydride or (ii) a dicarboxylic acid anhydride or (iii) a combination of an aliphatic monocarboxylic acid anhydride and a dicarboxylic acid anhydride in the presence of an aliphatic carboxylic acid as a reaction diluent in two or more separate reactions, wherein in each reaction a different molar ratio [aliphatic carboxylic acid/anhydroglucose units of cellulose ether] is used to produce esters of the cellulose ether of different weight average molecular weights.

Abstract: In a process for preparing an esterified cellulose ether a cellulose ether is esterified with (i) an aliphatic monocarboxylic acid anhydride or (ii) a dicarboxylic acid anhydride or (iii) a combination of an aliphatic monocarboxylic acid anhydride and a dicarboxylic acid anhydride in the presence of an alkali metal carboxylate and an aliphatic carboxylic acid, wherein the molar ratio [alkali metal carboxylate/anhydroglucose units of cellulose ether] is not more than [1.20/1] and the molar ratio [aliphatic carboxylic acid/anhydroglucose units of cellulose ether] is from [3.55/1] to [9.0/1].

Abstract: Novel hydroxyalkyl methyl cellulose acetate succinates which a) have from 4.0 to less than 10.0 weight percent of succinoyl groups, b) have a weight average molecular weight Mw of from 80,000 Dalton to 350,000 Dalton, and c) exhibit a turbidity of up to 41 NTU as a 1.5 weight percent solution in acetone; and novel hydroxyalkyl methyl cellulose acetate succinates which a) have from 10.0 to 20.0 weight percent of succinoyl groups, b) have a weight average molecular weight Mw of from 80,000 Dalton to 350,000 Dalton, and c) exhibit a turbidity of up to 37 NTU as a 1.5 weight percent solution in acetone are useful for preparing solid dispersion of active ingredients in these hydroxyalkyl methyl cellulose acetate succinates.

Abstract: Esterified cellulose ethers which have i) 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, ii) a weight average molecular weight Mw of from 80,000 Dalton to 350,000 Dalton, iii) a Polydispersity Mw/Mn of from 1.3 to 4.1, and iv) a viscosity of up to 4.0 mPa s, measured as a 2.0 wt % solution of the esterified cellulose ether in 0.43 wt % aqueous NaOH at 20° C., are useful as enteric polymers for pharmaceutical dosage forms.

Abstract: A partially cross-linked esterified cellulose ether having A) groups of the formula —C(O)—R—COOA or 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, and B) having a molecular weight distribution such that [Wf(>100 k)?Wf(>100 k)XL]/Wf(>100 k)XL is at least 0.20, wherein Wf(>100 k) is the total weight fraction of the esterified cellulose ether that exceeds 100,000 g/mol, and Wf(>100 k)XL is the weight fraction that exceeds 100,000 g/mol of the methylated esterified cellulose ether is useful as enteric polymer for pharmaceutical dosage forms.

Abstract: Two or more esters of a cellulose ether, each having the same ether and ester substituents but different weight average molecular weights are prepared in a process which comprises the steps of esterifying a cellulose ether with (i) an aliphatic monocarboxylic acid anhydride or (ii) a dicarboxylic acid anhydride or (iii) a combination of an aliphatic monocarboxylic acid anhydride and a dicarboxylic acid anhydride in the presence of an alkali metal carboxylate in two or more separate reactions, wherein in each reaction a different molar ratio [alkali metal carboxylate/anhydroglucose units of cellulose ether] is used to produce esters of the cellulose ether of different weight average molecular weights.

Abstract: A liquid composition comprises an organic diluent and at least one cellulose ether having anhydroglucose units joined by 1-4 linkages and having methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl as substituents such that hydroxyl groups of anhydroglucose units are substituted with methyl groups such that s23/s26 is 0.29 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxyl groups in the 2- and 3-positions of the anhydroglucose unit are substituted with a methyl group and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxyl groups in the 2- and 6-positions of the anhydroglucose unit are substituted with a methyl group. The liquid composition can be used for preparing a solid dispersion of an active ingredient in a cellulose ether.

Abstract: An esterified cellulose ether comprises (i) aliphatic monovalent acyl groups or (ii) 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 or (iii) a combination of aliphatic monovalent acyl groups and groups of the formula —C(O)—R—COOA, wherein the cellulose ether has anhydroglucose units joined by 1-4 linkages and has methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl as substituents such that the esterified cellulose ether has an MS (hydroxyalkyl) of 0.05 to 1.00, and hydroxyl groups of anhydroglucose units are substituted with methyl groups such that [s23/s26?0.2*MS(hydroxyalkyl)] is 0.

Abstract: A melt-extruded polymer composition comprising a) at least one cellulose ether, b) one or more active ingredients and c) one or more optional additives, wherein said at least one cellulose ether has an MS (hydroxyalkyl) of 0.05 to 0.55 and hydroxyl groups of anhydroglucose units are substituted with methyl groups such that [s23/s26?0.2*MS(hydroxyalkyl)] is 0.32 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxyl groups in the 2- and 3-positions of the anhydroglucose unit are substituted with a methyl group and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxyl groups in the 2- and 6-positions of the anhydroglucose unit are substituted with a methyl group.

Abstract: A sustained release dosage form comprises an active ingredient blended with a polymeric matrix. At least a portion of the polymeric matrix is formed by a cellulose ether having an onset dissolution temperature of at least 40° C., having anhydroglucose units joined by 1-4 linkages and having methyl groups, hydroxyalkyl groups, and optionally alkyl groups being different from methyl as substituents such that the cellulose ether has an MS (hydroxyalkyl) of 0.05 to 1.00, and hydroxyl groups of anhydrogluclose units are substituted with methyl groups such that [s23/s26?0.2*MS(hydroxyalkyl)] is 0.31 or less, wherein s23 is the molar fraction of anhydroglucose units wherein only the two hydroxyl groups in the 2- and 3-positions of the anhydroglucose unit are substituted with a methyl group and wherein s26 is the molar fraction of anhydroglucose units wherein only the two hydroxyl groups in the 2- and 6-positions of the anhydroglucose unit are substituted with a methyl group.

Abstract: A reaction product mixture is obtained from a reaction of (a) a cellulose ether with (b) an aliphatic monocarboxylic acid anhydride or with a di- or tricarboxylic acid anhydride or with a combination of an aliphatic mono-carboxylic acid anhydride and a di- or tri-carboxylic acid anhydride in the presence of (c) an aliphatic carboxylic acid. A process for precipitating an esterified cellulose ether from this reaction product mixture comprises the step of contacting the reaction product mixture with water and subjecting the combination of water and the reaction product mixture to a shear rate of at least 800 s?1. The precipitated esterified cellulose ether can be recovered as a non-tacky product.

Abstract: The invention is directed to a process of preparing carboxymethyl cellulose comprising the steps of (a) reacting non-regenerated cellulose with an alkalization agent in the presence of water and isopropyl alcohol and (b) reacting the alkalized cellulose with monohaloacetic acid or a salt thereof, wherein 1.0 to 1.6 mol of the alkalization agent and 15 to 30 mol of water are used in step (a) and 0.5 to 0.8 mol of monohaloacetic acid or a salt thereof are used in step (b), each based on 1 mol of anhydroglucose unit of the cellulose. The invention also relates to carboxymethyl cellulose prepared by that process.