Capsule filling with Active Pharmaceutical Ingredients

Filling capsules with active pharmaceutical ingredients (APIs) is a critical step in pharmaceutical manufacturing.
The process ensures accurate dosing and uniform distribution of the API within the capsule, providing a reliable and
convenient dosage form for patients.

1. Preparing the API Formulation

Before the filling process begins, the API formulation must be carefully prepared. This includes blending the API
with appropriate excipients to ensure proper flowability and homogeneity. The excipients may include fillers,
diluents, binders, lubricants, and disintegrants, depending on the specific requirements of the capsule
formulation.

2. Capsule Shells

Capsules come in two main types: hard gelatin capsules and soft gelatin capsules. Hard gelatin capsules are typically
used for solid formulations, while soft gelatin capsules are used for liquid or semi-solid formulations. The
appropriate capsule size is selected based on the required dosage strength and the amount of API and excipients to be filled.

3. Capsule Filling Machines

Capsule filling is performed using specialized machines known as capsule filling machines or capsule fillers. These
machines are designed to efficiently fill a large number of capsules in a precise and automated manner. There are
various types of capsule filling machines, including manual, semi-automatic, and fully automatic machines. The choice
of machine depends on the production scale and the complexity of the formulation.

4. Dosage Filling

The capsule filling machine is set up with the appropriate tooling and adjusted to ensure accurate dosing of the API
formulation into each capsule. The machine consists of a hopper that holds the formulation and a dosing mechanism
that dispenses the correct amount of the formulation into each capsule. The dosing mechanism may use different
methods such as tamping pins, dosing discs, or dosing rings to fill the capsules.

5. Tamping and Compression

In the case of hard gelatin capsules, after dosing the formulation into the capsules, tamping pins or compression
paddles may be used to compact the formulation inside the capsules. This ensures that the correct amount of
formulation is packed into each capsule and eliminates air pockets, providing uniformity in dosing.

6. Sealing the Capsules

After the capsules are filled with the API and any additional excipients, the two halves of the hard gelatin
capsules are joined together using a process known as capsule sealing. The sealing ensures that the capsule contents
remain intact and protected until the capsule is ingested.

7. Quality Control

Throughout the capsule filling process, quality control checks are conducted to ensure accurate dosing, weight
uniformity, and proper sealing. 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

Filling capsules with active pharmaceutical ingredients (APIs) is a precise and critical process in pharmaceutical
manufacturing. By using specialized capsule filling machines and following strict quality control measures, the
pharmaceutical industry ensures that capsules are accurately dosed, uniformly filled, and effectively sealed to
deliver safe and effective medications to patients.