Abstract: A process for making 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 cellulose ether acetate phthalate is provided, wherein the degree of substitution of phthalyl groups is from 0.02 to 0.25, the degree of neutralization of phthalyl groups is not more than 0.5, the degree of substitution of acetyl groups is from 0.02 to 0.40, and the total degree of substitution of phthalyl and acetyl groups is not more than 0.50. The cellulose ether acetate phthalate has a solubility in water of at least 2.0 weight percent at 2° C.

Abstract: An aqueous composition comprising a cellulose ether acetate being at least partially dissolved in an aqueous liquid is produced in a process, wherein an aqueous liquid is mixed with a cellulose ether acetate having a degree of substitution of acetyl groups, DSAc, of from 0.05 to 0.75 and the temperature of the mixture of the cellulose ether acetate and the aqueous liquid is set to less than 10 C to at least partially dissolve the cellulose ether acetate in the aqueous liquid.

Abstract: An esterified cellulose ether comprising aliphatic monovalent acyl groups and groups of the formula —C(O)—R—COOH, R being a divalent hydrocarbon group, has the following properties: i) the degree of neutralization of the groups —C(O)—R—COOH is not more than 0.4, ii) the total degree of ester substitution is from 0.10 to 0.70, and iii) the esterified cellulose ether has a solubility in water of at least 2.0 weight percent at 2 C.

Abstract: A process for producing an esterified cellulose ether can be efficiently be produced by reacting a moist cellulose ether having a water content of at least 10 percent, based on the weight of the moist cellulose ether, with an aliphatic monocarboxylic acid anhydride, a dicarboxylic acid anhydride or a combination thereof. Further improvements in efficiency and reduction in process steps are achieved in a process for producing an esterified cellulose ether which comprises the steps of a) reacting cellulose with an alkaline material to produce alkali cellulose, b) reacting the produced alkali cellulose with one or more etherifying agents and washing the produced cellulose ether to obtain a moist cellulose ether having a water content of at least 10 weight percent, and c) reacting the moist cellulose ether with an aliphatic monocarboxylic acid anhydride and/or a dicarboxylic acid anhydride and with a depolymerizing agent.

Abstract: A composition comprising a) an esterified cellulose ether comprising aliphatic monovalent acyl groups and groups of the formula —C(O)—R—COOH, R being a divalent hydrocarbon group, wherein I) the degree of neutralization of the groups —C(O)—R—COOH is not more than 0.4 and II) the total degree of ester substitution is from 0.03 to 0.70, and b) a cellulose ether having a viscosity of from 1.2 to 200 mPa s, measured as a 2 weight-% aqueous solution at 20° C., gels at increased temperature and displays reduced syneresis when further increasing the temperature of the gel.

Abstract: Esterified cellulose ethers which comprise (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, which have a viscosity of up 19 mPa·s, measured as a 10 wt % solution of the esterified cellulose ether in acetone at 20° C. and which have a weight average molecular weight Mw of at least 90,000 Dalton, are useful for preparing solid dispersions comprising drugs.

Abstract: An aqueous composition which is useful for producing coatings and capsule shells comprises a) dispersed particles of an esterified cellulose ether comprising (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 hydrocarbon group and A is hydrogen or a cation, and the total degree of ester substitution is more than 0.70, and b) an esterified cellulose ether comprising aliphatic monovalent acyl groups and groups of the formula —C(O)—R—COOH, R being a divalent hydrocarbon group, wherein I) the degree of neutralization of the groups —C(O)—R—COOH is not more than 0.4, II) the total degree of ester substitution is from 0.03 to 0.70, and III) the esterified cellulose ether b) has a solubility in water of at least 2.0 weight percent at 2° C.

Abstract: In a water-redispersible polymer powder—the polymer is at least one esterified cellulose ether comprising (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, and—the polymer powder comprises from 0.05 to 20 percent of at least one salt of a fatty acid, based on the weight of the esterified cellulose ether(s).

Abstract: Capsule shells and coatings can be prepared from an aqueous composition comprising a) at least 20 percent, based on the total weight of the aqueous composition, of a dispersed esterified cellulose ether comprising (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, b) from 0.05 to 20 percent of a salt of a fatty acid, based on the weight of the dispersed esterified cellulose ether, and c) from 0.01 to 10 percent of an anionic surfactant comprising a sulfate or sulfonate group, based on the weight of the dispersed esterified cellulose ether.

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 Mw 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 Mw of at least 310,000 Dalton are useful for preparing solid dispersions comprising drugs.

Abstract: An esterified cellulose ether of increased weight average molecular weight is produced in a process for reacting a cellulose ether with an aliphatic monocarboxylic acid anhydride and a dicarboxylic acid anhydride, wherein the process comprises the steps of a) preparing a reaction mixture comprising the cellulose ether, the dicarboxylic acid anhydride and a reaction diluent and heating the reaction mixture to a temperature of from 60 C to 110 C prior to, during or after mixing the components of the reaction mixture, and b) adding continuously or in at least three portions the monocarboxylic acid anhydride to the reaction mixture of step a) and completing the reaction.

Abstract: A modified process for producing an esterified cellulose ether is provided which comprises the stages of i) preparing a reaction mixture comprising a cellulose ether, an aliphatic monocarboxylic acid anhydride, a dicarboxylic acid anhydride, and a reaction diluent and heating the reaction mixture to a temperature of from 60° C. to 110° C. prior to, during or after mixing the components of the reaction mixture to conduct an esterification reaction, and ii) before the esterification reaction is completed, adding an additional amount of reaction diluent continuously or in one or more portions to the reaction mixture and allowing the esterification reaction to further proceed.

Abstract: An aqueous composition comprising an esterified cellulose ether being at least partially dissolved in an aqueous liquid, wherein the esterified cellulose ether comprises groups of the formula —C(O)—R—COOH, wherein R is a divalent hydrocarbon group is produced in a process which comprises the step of a) mixing the esterified cellulose ether with the aqueous liquid, and b) maintaining or adjusting the degree of neutralization of the groups —C(O)—R—COOH of the esterified cellulose ether at or to less than 0.45 and setting the temperature of the mixture of the esterified cellulose ether and the aqueous liquid to less than 10 C to at least partially dissolve the esterified cellulose ether in the aqueous liquid.

Abstract: An esterified cellulose comprising aliphatic monovalent acyl groups and groups of the formula —C(O)—R—COOH, R being a divalent hydrocarbon group, has the following properties: i) the degree of neutralization of the groups —C(O)—R—COOH is not more than 0.4, ii) the total degree of ester substitution is from 0.03 to 0.38, and iii) the esterified cellulose ether has a solubility in water of at least 2.0 weight percent at 20° C.

Abstract: 1. An esterified cellulose ether which i) comprises groups of the formula —C(O)—R—COOH or a combination of aliphatic monovalent acyl groups and groups of the formula —C(O)—R—COOH, wherein R is a divalent hydrocarbon group, ii) has a weight average molecular weight Mw of up to 70,000 Dalton, iii) has a degree of neutralization of the groups —C(O)—R—COOH of not more than 0.4, and iv) has a solubility in water of at least 2.0 weight percent at 2° C., is useful for preparing enteric capsules.

Abstract: An esterified cellulose ether comprising aliphatic monovalent acyl groups and groups of the formula —C(O)—R—COOH, R being a divalent hydrocarbon group, has the following properties: i) the degree of neutralization of the groups —C(O)—R—COOH is not more than 0.4, ii) the total degree of ester substitution is from 0.10 to 0.70, and iii) the esterified cellulose ether has a solubility in water of at least 2.0 weight percent at 2 C.

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 Mw 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 Mw of at least 310,000 Dalton are useful for preparing solid dispersions comprising drugs.

Abstract: A process for preparing an ester of a cellulose ether comprises the steps of reacting a cellulose ether with a dicarboxylic acid anhydride or with a combination of a dicarboxylic acid anhydride and an aliphatic monocarboxylic acid anhydride, wherein the esterification is conducted i) in the absence of an esterification catalyst or in the presence of no more than 0.1 mole of an esterification catalyst per mole of anhydroglucose units of cellulose ether, and ii) in the presence of an aliphatic carboxylic acid, wherein the molar ratio [aliphatic carboxylic acid/anhydroglucose units of cellulose ether] is up to 12/1.

Abstract: A process for fractionating an esterified cellulose ether comprising groups of the formula —C(O)—R—COOH, wherein R is a divalent hydrocarbon group, comprises the steps of a) blending the esterified cellulose ether comprising groups of the formula —C(O)—R—COOH with an aqueous liquid and setting the temperature of the resulting blend to less than 10° C. to dissolve a portion of the esterified cellulose ether in the aqueous liquid, b) separating the non-dissolved portion of the esterified cellulose ether from the remainder of the blend, and c) recovering or disposing of the esterified cellulose ether that is dissolved in the aqueous liquid.