Bloom Strength of Soft Gelatin Capsules

Understand Bloom Strength of Soft Gelatin Capsule

Soft gelatin capsules are widely used in the pharmaceutical and nutraceutical industries to encapsulate liquid or semi-solid ingredients. The bloom strength of soft gelatin capsules plays a critical role in determining the gel’s mechanical properties, influencing its durability, elasticity, and dissolution behavior. Ensuring optimal bloom strength is essential for maintaining capsule integrity during storage, transportation, and consumption.

The Role of Bloom Strength for Gelatin Capsule

What Is Bloom Strength?

Bloom strength refers to the firmness or gel strength of gelatin, measured in grams using a bloom tester. It quantifies the force required to depress a standard-sized plunger into a prepared gelatin sample under specific conditions. A higher bloom strength indicates a firmer and more elastic gel, while a lower bloom strength suggests a softer, more flexible gelatin structure.

Why Bloom Strength Matters in Soft Gelatin Capsules

1. Encapsulation Integrity: Ensures capsules maintain shape and prevent leakage.
2. Controlled Dissolution: Regulates how quickly active ingredients are released.
3. Manufacturing Efficiency: Optimized bloom strength prevents capsule defects.
4. Product Stability: Reduces the risk of capsule breakage during handling.

How to Measure Bloom Strength Using Bloom Tester

A bloom tester is the primary instrument used to determine gelatin strength. The testing process follows these steps:

1. Preparation of Gelatin Sample: A standard 6.67% gelatin solution is prepared and allowed to set under controlled conditions.
2. Plunger Application: A calibrated plunger is lowered onto the gelatin surface.
3. Force Measurement: The tester records the force required to depress the plunger 4 mm into the gel.
4. Result Analysis: The recorded force, in grams, represents the bloom strength.

Factors Affecting Bloom Strength in Soft Gelatin Capsule

Several factors influence the bloom strength of gelatin, including:

• Gelatin Source & Processing: Variability in raw materials impacts gel quality.
• pH & Temperature: Changes in formulation conditions alter gel properties.
• Moisture Content: Higher moisture can reduce gel strength and capsule integrity.
• Additives & Plasticizers: Ingredients such as glycerin affect flexibility and hardness.

CHT-01 Capsule and Softgel Hardness Tester

For precise testing of gelatin capsule properties, the CHT-01 Capsule and Softgel Hardness Tester by Cell Instruments is an ideal solution. This instrument evaluates not only the bloom strength but also capsule elasticity, seal integrity, and mechanical resistance. It features:

• Multi-test programs for comprehensive analysis.
• Rotating table to improve efficiency.
• Automatic data recording for consistent results.
• Adjustable test speeds for varied applications.

The bloom strength of soft gelatin capsules is a vital parameter in pharmaceutical quality control. It ensures encapsulation reliability, proper dissolution rates, and overall product stability. Using a bloom tester or a specialized hardness tester like the CHT-01 Capsule and Softgel Hardness Tester guarantees accurate, repeatable results, helping manufacturers maintain high-quality standards. Investing in precise testing equipment enhances production efficiency and consumer confidence in soft gelatin capsule products.