Accelerated drying of soft capsules in a controlled environment

Patent metadata

Field	Value
Publication number	US-11026865-B2
Application number	US-201716467436-A
Country	US
Kind code	B2
Filing date	Dec 8, 2017
Priority date	Dec 8, 2016
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A method of drying soft capsules including steps of: a) supplying a flow of air to said soft capsules at a velocity of the air across the soft capsules of from about 0.15 m/s to about 13 m/s; b) increasing, over time, a drying temperature to which said soft capsules are exposed while ensuring that the drying temperature remains below a melting temperature of a capsule shell of the soft capsules; c) exposing said soft capsules to an initial relative humidity of from about 49% RH to about 79% RH; d) decreasing the relative humidity to which the soft capsules are exposed as the capsules dry until an equilibrium relative humidity of the soft capsules reaches a desired relative humidity; and e) exposing the soft capsules from step d) to a temperature of from 20-25° C. Also disclosed is a drying system for carrying out the method.

First claim

What is claimed is:

1. A method of drying soft capsules comprising steps of:
a) supplying an airflow to said soft capsules at a velocity of the air across the soft capsules of from about 0.15 m/s to about 13 m/s;
b) increasing, over time, a drying temperature to which said soft capsules are exposed while ensuring that the drying temperature remains below a melting temperature of a capsule shell of the soft capsules;
c) exposing said soft capsules to an initial relative humidity of from about 49% RH to about 79% RH;
d) decreasing the relative humidity to which the soft capsules are exposed as the capsules dry until an equilibrium relative humidity of the soft capsules reaches a desired relative humidity; and
e) exposing the soft capsules from step d) to a temperature of from 20-25° C.

2. The method of claim 1 further comprising a step of:
decreasing the velocity of the airflow to which the soft capsules are exposed, as the soft capsules dry.

3. The method of claim 1 , wherein the relative humidity is controlled so that a differential between the relative humidity to which the soft capsules are exposed and the equilibrium relative humidity of the soft capsules is maintained at about 15% dRH to about 35% dRH.

4. The method of claim 1 , wherein the soft capsules are lipophilic.

5. The method of claim 4 , wherein the initial relative humidity is from about 49% RH to about 79% RH.

6. The method of claim 1 , wherein a lowest relative humidity to which the soft capsules are exposed is from about 10% RH to about 24% RH.

7. The method of claim 1 , wherein the soft capsules are hydrophilic.

8. The method of claim 7 , wherein the wherein the initial relative humidity is from about 49% RH to about 79% RH and a lowest relative humidity to which the soft capsules are exposed is from about 23% RH to about 57% RH.

9. A drying system for drying soft capsules comprising:
at least one dryer;
a unit in fluid communication with the dryer to provide an airflow to the dryer;
a humidifier configured to be able to increase a relative humidity within the dryer;
a heater configured to be able to increase a temperature of air in the dryer; and
a flow control valve configured to control an amount of the airflow from the unit to the dryer;
wherein the heater is configured to increase the temperature over time according to a temperature ramp based on a melting point of a capsule shell of the soft capsules and a combination of the flow control valve and the humidifier is configured to control the relative humidity in the dryer such that the relative humidity in the dryer decreases over time from an initial relative humidity of 49% RH to 79% RH to an endpoint relative humidity of 10% RH to 24% RH, and the relative humidity is decreased in a manner whereby a differential between the relative humidity in the dryer and the equilibrium relative humidity of the soft capsules is maintained at 15% dRH to 35% dRH.

10. The drying system of claim 9 , further comprising a recirculation fan located and configured to recirculate a return air stream from an exhaust of the dryer to the unit that provides the airflow to the dryer.

11. The drying system of claim 10 , wherein the humidifier comprises the recirculation fan.

12. The drying system of claim 9 , further comprising a recirculation fan located and configured to recirculate a return air stream from an exhaust of the dryer to the unit that provides the airflow to the dryer, and wherein the flow control valve is configured such that reducing the amount of airflow from the unit to the dryer increases the relative humidity within the dryer and increasing the amount of airflow from the unit to the dryer decreases the relative humidity within the dryer.

13. The drying system of claim 9 , wherein a combination of the flow control valve and the humidifier is configured to control the relative humidity in the dryer such that the relative humidity in the dryer decreases over time from an initial relative humidity of about 49% RH to about 79% RH to an endpoint relative humidity of about 23% RH and about 57% RH.

14. A method of drying soft capsules, said method comprising steps of:
a) supplying a flow of air to said capsules at a velocity of the air across the soft capsules of from about 0.15 m/s to about 13 m/s;
b) increasing, over time, a drying temperature to which said soft capsules are exposed while ensuring that the drying temperature remains below a melting temperature of a capsule shell;
c) maintaining a differential between a relative humidity in a dryer and an equilibrium relative humidity of the soft capsules of about 15% dRH to about 35% dRH until the equilibrium relative humidity of the soft capsules reaches a desired relative humidity; and
d) exposing the soft capsules from step c) to a temperature of from 20-25° C.

Assignees

• Scherer Technologies Llc R P

Inventors

• Hart Norton Richard
• Fulper Lester David

Classifications

• F26B21/50

  Ducting arrangements from the source of air or other gases to the materials or objects being dried · CPC title

• F26B21/37

  Velocity of flow; Quantity of flow · CPC title

• F26B21/35 Primary

  Temperature; Pressure · CPC title

• F26B21/33

  Humidity · CPC title

• F26B21/25

  partly outside the drying enclosure · CPC title