Filling Process for Soft Gelatin Capsules

Soft gelatin capsules (SGC) are popular dosage forms used to deliver liquid or semi-solid formulations. The filling
process for soft gelatin capsules involves several steps to ensure accurate dosing and uniformity in each capsule.
Below, is a typical process of filling soft gelatin capsules:

1. Gelatin Shell Preparation

The soft gelatin capsule filling process starts with the preparation of the gelatin shells. The gelatin is mixed with
plasticizers and other excipients to achieve the desired shell properties, such as flexibility and stability. The
gelatin mixture is then heated and formed into two halves of the capsule shell using specialized capsule molds.

2. Cooling and Moistening

After the gelatin shells are formed, they are cooled and solidified to maintain their shape. Before filling, the
shells are moistened slightly to prevent them from sticking to the filling machine and to ensure better adherence
between the two halves during the encapsulation process.

3. Filling the Liquid Formulation

The liquid or semi-solid formulation to be filled into the soft gelatin capsules is prepared separately. The
formulation may contain the active pharmaceutical ingredient (API), along with other excipients, oils, suspensions,
or solutions. The formulation should have suitable flow properties to ensure smooth and precise filling into the
capsules.

4. Encapsulation Process

The encapsulation process is where the gelatin shells are filled with the liquid formulation. The process typically
involves the use of a rotary die encapsulation machine. The main steps in the encapsulation process are as follows:

a. Spreading the Shells

The two halves of the soft gelatin capsules are spread apart using a mechanical system. This creates a space for the
liquid formulation to be filled between the two halves.

b. Filling the Formulation

The liquid formulation is precisely dispensed into the space between the two halves of the gelatin shells. The
filling is carefully controlled to ensure that each capsule receives the correct dosage of the formulation.

c. Sealing the Capsules

After the liquid formulation is filled, the two halves of the gelatin shells are brought together and pressed
firmly. The pressure causes the gelatin shells to fuse, creating a hermetically sealed soft gelatin capsule that
encloses the liquid formulation.

5. Drying and Inspection

Once the soft gelatin capsules are sealed, they undergo a drying process to remove excess moisture and ensure
stability. The capsules are then inspected for quality and uniformity. Capsules that do not meet the specified
quality criteria are rejected, and the necessary adjustments are made to the filling process to maintain product
quality and consistency.

Conclusion

The filling process for soft gelatin capsules involves precise and automated techniques to ensure accurate dosing
and uniformity in each capsule. The soft gelatin capsules offer an effective way to deliver liquid or semi-solid
formulations, providing a convenient and easy-to-swallow dosage form for patients.