The production of soft gelatin capsules involves the following steps:
1) Formulation of Fill Material:
Drugs are dissolved or suspended in a suitable vehicle (e.g., oils, polyethylene glycol, or other non-aqueous solvents).
The formulation is homogenized to ensure uniformity.
2) Preparation of Gelatin Mass:
Gelatin, plasticizers, and other components are mixed with water and heated under vacuum to remove air bubbles.
The gelatin mass is held at a controlled temperature (~50°C) to maintain its fluidity.
3) Encapsulation Process:
The encapsulation is typically performed using a rotary die process:
Two ribbons of gelatin are formed and fed into the rotary die machine.
The fill material is injected between the ribbons.
The ribbons are sealed and cut into individual capsules.
4) Drying:
Capsules are tumbled in rotating drums to remove excess moisture.
Further drying occurs in controlled drying tunnels with regulated temperature (20-25°C) and humidity (20-30%).
5) Inspection and Sorting:
Capsules are visually inspected for defects like leaks, cracks, or improper sealing.