Messi Biology states that soft capsules (softgels), as a widely used dosage form in nutritional supplements and pharmaceuticals, offer advantages such as good palatability, rapid absorption, and ease of swallowing. However, during production, packaging, and storage, soft capsules are prone to adhesion (sticking together), which affects their appearance and the consumer experience, and may even lead to product scrapping. To address this issue, magnesium carbonate is widely utilized in the anti-sticking treatment of soft capsules, playing a critical role in processing and stability.
I. Physical Properties and Anti-Sticking Principle of Magnesium Carbonate
- Strong Hydrophobicity: Magnesium carbonate possesses a certain degree of hydrophobicity. It can form a dry granular film on the capsule surface, reducing the occurrence of moisture-induced adhesion.
- Moderate Hygroscopicity: Magnesium carbonate can absorb a portion of surface moisture (water vapor), thereby lowering the humidity on the capsule surface and inhibiting the formation of condensation.
- Suitable Particle Size: Micronized magnesium carbonate offers excellent coverage. It can be evenly distributed across the capsule surface without affecting the capsule’s gloss or texture.
II. Application Methods
- External Dry Powder Treatment: After the soft capsules are formed, magnesium carbonate powder is lightly applied via tumbling or sieving equipment.
- Mixed Use with Talc or Silica: In some processes, it is compounded with other inert powders to enhance the overall anti-sticking effect.
- Suitable for High-Humidity and High-Temperature Packaging Environments: It is particularly suitable for hot and humid climates, such as in the Asian region, effectively extending shelf life.
III. Advantages for Finished Product Quality
- Prevents capsules from sticking to one another, improving the efficiency of packaging automation.
- Does not react with the capsule contents; it is chemically stable and safe.
- Light magnesium carbonate meeting food or pharmacopoeia standards is available to satisfy different regulatory requirements.
IV. Precautions
- The particle size of the magnesium carbonate must be moderate; if it is too coarse, it will affect the feel of the capsule, while if it is too fine, it may create floating dust.
- The dosage must be controlled within a reasonable range to prevent excess powder residue from negatively affecting the consumer experience.
- It is recommended to use dedicated dedusting devices and airflow cleaning equipment to ensure the finished product is clean.