Why Do Softgel Capsules Leak? Key Causes in Manufacturing and Handling

Softgel capsules are a common dosage form in dietary supplement manufacturing due to their ability to contain liquid or semi-solid fills. However, leakage can occur if formulation, process, or handling factors are not properly controlled. Understanding the causes of softgel capsule leakage helps brands and manufacturers reduce quality risks and improve product consistency.

At CSK Biotech, we provide OEM and ODM manufacturing for softgel capsules alongside other supplement formats, supporting global brands with structured production and quality management systems.

What Is Softgel Capsule Leakage?

Softgel capsule leakage refers to the escape of fill material through the capsule shell or seam. This may occur during production, storage, transportation, or extended holding periods and is typically associated with capsule integrity rather than product use.

Common Reasons Softgel Capsules Leak

1. Fill and Shell Incompatibility

Certain oils, solvents, or active materials may interact with the capsule shell, which can:

• Weaken shell structure

• Increase shell permeability

• Affect long-term capsule stability

Compatibility assessment is an essential step in softgel formulation development.

2. Improper Fill Viscosity

If the fill material is:

• Too low in viscosity, it may migrate through the shell

• Too high in viscosity, it may place uneven pressure on the capsule seam

Maintaining consistent viscosity helps support capsule integrity.

3. Capsule Shell Composition

Softgel shells typically contain gelatin, plasticizers, and water. Leakage risks may increase if:

• Shell thickness is inconsistent

• Plasticizer ratios are not optimized

• Moisture content is outside controlled ranges

Shell formulation consistency is critical to capsule performance.

4. Encapsulation and Sealing Parameters

During production, factors such as:

• Sealing temperature

• Pressure at the capsule seam

• Alignment of encapsulation tooling

directly affect seam strength. Inadequate sealing can result in weak points prone to leakage.

5. Drying and Conditioning Process

After encapsulation, softgels must undergo controlled drying and conditioning. Issues may arise if:

• Drying time is insufficient

• Temperature or humidity is not properly controlled

• Capsules are unevenly exposed during curing

Proper conditioning allows the shell to stabilize before packaging.

6. Storage and Transportation Conditions

Post-production handling can also influence leakage, including:

• High temperature exposure

• Excess humidity

• Physical stress during transport

Environmental controls help maintain capsule integrity over time.

How Manufacturers Minimize Leakage Risks

Experienced softgel manufacturers apply multiple control measures, including:

• Pre-production compatibility evaluations

• Controlled encapsulation and drying parameters

• In-process seam inspection

• Environmental monitoring during storage

These measures help maintain consistent quality across batches.

The Role of Manufacturing Expertise

Softgel production requires specialized equipment and process control. Manufacturers with established experience can:

• Identify potential risks early in development

• Optimize shell and fill parameters

• Support stable, scalable production

This expertise is essential for long-term product consistency.

Partner with CSK Biotech for Softgel Capsule Manufacturing

CSK Biotech provides OEM and ODM manufacturing for softgel dietary supplements, offering:

• Controlled softgel encapsulation processes

• GMP-aligned quality management systems

• Support for custom formulations and private label production

• Manufacturing suitable for international markets

To discuss softgel capsule manufacturing or quality considerations, please contact:

📧 steve@cskbiotech.com

We welcome inquiries from global brands seeking reliable and compliant softgel supplement manufacturing solutions.