Water-soluble esterified cellulose ethers
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 M w 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.
1. An esterified cellulose ether
i) comprising groups of the formula —C(O)—CH 2 —CH 2 —COOH or a combination of acetyl groups and groups of the formula —C(O)—CH 2 —CH 2 —COOH,
ii) having a weight average molecular weight M w of up to 70,000 Dalton,
iii) having a degree of neutralization of the groups —C(O)—CH 2 —CH 2 —COOH of not more than 0.4, and
iv) having a solubility in water of at least 2.0 weight percent at 2° C.
2. The esterified cellulose ether of claim 1 having a Polydispersity M w /M n of not more than 2.0.
3. The esterified cellulose ether of claim 1 having a viscosity of up to 13 mPa·s, measured as a 10 wt.-% solution of the esterified cellulose ether in acetone at 20° C.
4. The esterified cellulose ether of claim 1 wherein at least 85 wt. % of the esterified cellulose ether is soluble in a mixture of 2.5 weight parts of the esterified cellulose ether and 97.5 weight parts of water at 2° C.
5. The esterified cellulose ether of claim 1 wherein at least 85 wt. % of the esterified cellulose ether is soluble in a mixture of 10 weight parts of the esterified cellulose ether and 90 weight parts of water at 2° C.
6. The esterified cellulose ether of claim 1 being hydroxypropyl methyl cellulose acetate succinate.
7. A liquid composition comprising at least one esterified cellulose ether of claim 1 dissolved in an aqueous diluent.
8. A liquid composition comprising at least one esterified cellulose ether of claim 1 and an organic diluent.
9. The liquid composition of claim 7 comprising at least 5 weight percent of the esterified cellulose ether, based on the total weight of the liquid composition.
10. A coated dosage form wherein the coating comprises at least one esterified cellulose ether of claim 1 .
11. A polymeric capsule shell comprising at least one esterified cellulose ether of claim 1 .
12. A capsule comprising a capsule shell of claim 11 and further comprising a drug or a nutritional or food supplement or a combination thereof.
13. A solid dispersion of at least one active ingredient in at least one esterified cellulose ether of claim 1 .
14. The liquid composition of claim 8 comprising at least 5 weight percent of the esterified cellulose ether, based on the total weight of the liquid composition.