What Are Hard Capsules?

 

Hard capsules, also known as hard-shell capsules, are one of the most common dosage forms used to deliver medicines and dietary supplements.

Their main distinction lies in their structure: they consist of two cylindrical parts (body and cap) that fit perfectly together to contain powders, granules, or even non-aqueous liquids.

In this article, we’ll take a closer look at what hard gelatin capsules are, their applications, and how they are produced.

Enjoy your reading.

 

What Are Hard Gelatin Capsules?

 

Hard gelatin capsules, also referred to as hard-shell capsules, are among the most traditional and versatile dosage forms used in the pharmaceutical and dietary supplement industries.

Made mostly from animal-derived gelatin, typically bovine or porcine, they are valued for their effectiveness, safety, and versatility in administering powders or granules.

They also offer logistical and operational advantages: lightweight, easy to transport and store, and compatible with a wide range of encapsulation machines.

 

What Are Hard Gelatin Capsules Used For?

 

Hard capsules are a highly efficient and versatile solution for delivering active ingredients across various industries, particularly in the pharmaceutical, nutraceutical, and cosmetic sectors.

They are perfect for:

1 – Encapsulating solid substances;

2 – Protecting sensitive ingredients;

3 – Facilitating oral administration;

4 – Improving treatment adherence;

5 – Allowing flexible dosing.

 

1 – Encapsulating Solid Substances

 

Hard capsules are an efficient solution for containing powdered or granular ingredients, facilitating handling and precise dosing.

They provide physical protection to the contents while preserving the integrity of active ingredients during transport, storage, and consumption.

 

2 – Protecting Sensitive Ingredients

 

Many active compounds become unstable when exposed to environmental factors such as light, air, or moisture.

Capsules act as a barrier, extending shelf life and preserving effectiveness until administration.

 

3 – Facilitating Oral Administration

 

Unpleasant tastes or odors may often hinder treatment adherence.

Capsules fully enclose the contents, masking taste or smell, and improving the overall experience.

 

4 – Improving Treatment Adherence

 

With a standardized design and smooth finish, capsules are easier to swallow and appear more appealing, two key factors that contribute to compliance.

 

5 – Allowing Flexible Dosing

 

Capsules can be tailored to adjust the amount of active ingredients, which are especially useful in clinical studies or patient-specific therapies.

 

How Are Hard Gelatin Capsules Manufactured?

 

Hard capsule production follows a highly controlled process to ensure safety, uniformity, and quality. The main steps include:

1 – Preparation of the gelatin solution;

2 – Dipping stainless-steel molds;

3 – Controlled drying;

4 – Stripping, trimming, and joining of halves;

5 – Inspection and packaging with quality control.

 

1 – Preparation of the Gelatin Solution

 

The process begins with preparing the gelatin solution, the main component of hard capsules.

Gelatin is dissolved in purified water under controlled heating and stirring until the target viscosity is achieved.

At this stage, colorants, preservatives, and opacifiers may be added, depending on the final product specifications. The formulation is rigorously adjusted to ensure stability and uniformity.

 

2 – Dipping Stainless-Steel Molds

 

After preparation, metallic molds (stainless-steel pins) are dipped into the liquid gelatin. The molds have the exact shape of the capsule body and cap.

Capsule thickness is determined by solution viscosity and immersion time. Molds are then slowly withdrawn, forming a thin gelatin film on their surface.

 

3 – Controlled Drying

 

The coated molds are transferred to drying tunnels, where ventilation and temperature are precisely managed to reduce moisture.

This step is crucial to ensure the required mechanical strength and form during handling or storage.

 

4 – Stripping, Trimming, and Joining of Halves

 

Once dried, capsules are removed from the molds and undergo an automated trimming process, precisely defining the length of each half.

The two parts (body and cap) are then assembled to form the complete capsule. Assembly may be through a simple fit (snap-on) or locking mechanism, depending on the intended use.

 

5 – Inspection and Packaging with Quality Control

 

Finally, capsules undergo visual and mechanical inspections to identify any defects in shape, color, thickness, or rigidity.

After passing quality tests, they are packaged under controlled conditions, ready for supply to the pharmaceutical or dietary supplement industries.

 

Conclusion

 

Hard gelatin capsules remain a well-established choice in the pharmaceutical and nutraceutical industries.

Their manufacturing process involves precision, technology, and strict quality control, ensuring a safe, stable, and efficient final product.

Gelco International is a global leader in high-performance gelatin production for hard capsules, meeting the highest international standards.

Our gelatin is engineered for excellent moldability, transparency, proper viscosity, and mechanical strength, thereby ensuring optimal stability and efficiency throughout the encapsulation process.

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