Process of Capsule Sealing and Banding

Capsule sealing and banding are essential steps in the capsule manufacturing process. After the capsules are filled
with the active pharmaceutical ingredient (API) and any additional excipients, sealing ensures that the capsule
contents remain intact and protected until the capsule is ingested. In some cases, banding may be applied to the
capsule to provide additional security and tamper-evidence. Let’s explore the process of capsule sealing and
banding:

1. Capsule Sealing

Capsule sealing is the process of joining the two halves of a hard gelatin capsule together after they have been
filled with the API and excipients. It

is crucial to ensure that the capsule contents remain securely contained and
protected from external factors that could compromise their stability and efficacy. The capsule sealing process
typically involves the following steps:

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a. Preparing the Capsule Shells

The two halves of the hard gelatin capsule are first separated into their individual parts. The capsule shells are
inspected to ensure there are no defects or deformities that could affect the sealing process.

b. Aligning the Capsule Halves

The filled capsule halves are carefully aligned with each other using precision machinery. The proper alignment is
crucial to ensure that the capsule contents are evenly distributed between the two halves and that they fit together
seamlessly.

c. Applying Moisture

To facilitate the sealing process, a thin layer of moisture is applied to the rim of one capsule half. The moisture
softens the gelatin, making it pliable and allowing it to fuse with the other capsule half.

d. Compression and Sealing

The two aligned capsule halves are brought together, and compression force is applied to fuse them together. The
pressure forms a secure seal around the edges of the capsule, preventing any leakage of the contents. The sealed
capsules are then separated from any excess gelatin that might have been squeezed out during the sealing process.

Pharma Tip: High variability in capsule weight due to uneven powder blending.

2. Capsule Banding

Capsule banding is an optional process that can be applied to hard gelatin capsules to provide additional security,
tamper-evidence, and branding. Banding involves placing a colored or transparent band around the middle of the
capsule shell. The process of capsule banding includes the following steps:

a. Band Selection

The band material is chosen based on factors such as the desired appearance, tamper-evidence features, and the
compatibility of the material with the capsule shell. Common materials used for banding include gelatin, Hypromellose (HPMC), and pullulan.

b. Band Application

The selected bands are applied to the filled and sealed capsules using specialized banding machines. The machines
wrap the bands securely around the middle of the capsules, ensuring that they are held in place firmly.

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c. Optional Printing or Branding

After the bands are applied, additional printing or branding may be added to the band’s surface. This can include
product information, dosage strength, brand logos, or other relevant details to enhance product identification and
branding.

Conclusion

Capsule sealing and banding are crucial steps in the finalization of hard gelatin capsules. Sealing ensures that the
capsule contents remain protected and securely contained, while banding adds an extra layer of tamper-evidence and branding possibilities. Together, these processes contribute to the overall quality, safety, and appearance of the
finished capsules, ensuring that patients receive reliable and convenient dosage forms.