Hydroxypropyl Methyl Cellulose Hard Capsules and Process of Manufacture

1 . An aqueous composition for manufacture of hard capsules, characterized in that it comprises, in an aqueous solvent, 15-25% by weight, based on the total weight of the aqueous composition, of a hydroxypropyl methyl cellulose (HPMC) having a methoxy content of 27.0-30.0% (w/w), a hydroxypropoxy content of 4.0-7.5% (w/w) and a viscosity of 3.5-6.0 cPs as a 2% weight solution in water at 20° C.

2 . The composition according to claim 1 , characterized in that the hydroxypropyl methyl cellulose has a viscosity of 4.0-5.0 cPs as a 2% weight solution in water at 20° C.

3 . The composition according to claim 1 or 2 , characterized in that it comprises 17-23% by weight based on the total weight of the aqueous composition, of the hydroxypropyl methyl cellulose.

4 . The composition according to claim 3 , characterized in that the aqueous solvent is water.

5 . A process for the manufacture of hydroxypropyl methyl cellulose hard capsules according to a dip coating process, characterized in that it comprises the steps of:

(a) providing an aqueous composition of a hydroxypropyl methyl cellulose having a methoxy content of 27.0-30.0% (w/w), a hydroxypropoxy content of 4.0-7.5% (w/w) and a viscosity of 3.5-6.0 cPs as a 2% weight solution in water at 20° C., wherein the concentration of the hydroxypropyl methyl cellulose in the aqueous composition is chosen to obtain a viscosity of the aqueous composition of 1000 to 3000 cPs measured at a temperature of 10° C. to 1.0° C. below the aqueous composition gelling temperature,

(b) pre-heating dipping pins so that they are at 55-95° C. when dipped into the aqueous composition,

(c) dipping the pre-heated dipping pins into the aqueous composition maintained at a temperature of 10° C. to 1.0° C. below its gelling temperature,

(d) withdrawing the dipping pins from the aqueous composition obtaining a film on the dipping pins and

(e) drying the film on the dipping pins at a temperature above the gelling temperature of the aqueous composition so as to obtain molded capsule shells on the pins.

6 . The process according to claim 5 , characterized in that the aqueous composition of step (a) is an aqueous composition as defined in any one of claims 1 to 5 .

7 . The process according to claim 5 or 6 , characterized in that the temperature of the pre-heated pins is 60-90° C.

8 . The process according to claim 7 , characterized in that the aqueous composition in step (b) is maintained at a temperature of 4° C. to 1.0° C. below its gelling temperature.

9 . The process according to claim 8 , characterized in that step (e) comprises a step:

(e1) subjecting the pins to a temperature of 50-90° C. and a relative humidity of 20-90%.

10 . The process of claim 9 , characterized in that the temperature is 55-85° C. and a relative humidity of 20-70%, preferably 60-85° C. a relative humidity of 20-60%.

11 . The process according to claim 10 , characterized in that the duration of step (e1) is 90-480 seconds.

12 . The process according to claim 11 , characterized in that it comprises, downstream to step (e1), a step:

(e2) subjecting the pins to a temperature of 30-60° C. and a relative humidity of 20-90%.

13 . The process according to claim 12 , characterized in that the duration of step (e2) is between 30 and 60 minutes.

14 . A hydroxypropyl methyl cellulose hard capsule shell characterized that it contains a hydroxypropyl methyl cellulose having a methoxy content of 27.0-30.0% (w/w), a hydroxypropoxy content of 4.0-7.5% (w/w) and a viscosity of 3.5-6.0 cPs as a 2% weight solution in water at 20° C.

15 . The capsule shell according to claim 14 , characterized in that it contains the hydroxypropoxy methyl cellulose in an amount between 70% and 99% by weight on the shell weight.

16 . A capsule shell, obtainable by the process as defined in any one of claims 5 to 6 .

17 . (canceled)