I. Applications in Hard Capsules

Hard capsules consist of two parts: the capsule body and the capsule cap. Gelatin is the main film-forming material, with the following application characteristics:

Molding and Support Function

When pharmaceutical gelatin is dissolved in water, it forms a gel system with a certain viscosity and elasticity. After cooling and shaping in a mold, it forms a hollow capsule shell with a regular shape and moderate strength. This capsule shell has good mechanical toughness and can withstand slight compression during filling and transportation, preventing breakage.

Protection of Drug Activity

The gelatin capsule shell has a dense structure, effectively isolating external moisture, oxygen, and light, preventing the powder or granular drugs inside the capsule from deliquescence, oxidation, or decomposition, thus stabilizing the drug's efficacy and extending its shelf life.

Control of Dissolution Rate

Gelatin gradually dissolves in the mild acidic or alkaline environment of the human gastrointestinal tract. By adjusting the molecular weight and degree of cross-linking of the gelatin, or by adding a small amount of excipients (such as hydroxypropyl methylcellulose), the dissolution rate of the capsule shell can be precisely controlled, achieving rapid drug release or targeted release (such as release in a specific part of the intestine).

II. Applications in Soft Capsules

Soft capsules are mostly sealed elastic capsules, often used to encapsulate oily drugs, suspensions, or high-concentration solutions. Gelatin's role in them is reflected in:

Matrix Forming Material

The capsule wall of soft capsules is made from a mixture of gelatin, plasticizers (such as glycerin), and water in a certain proportion. Gelatin provides the skeletal structure of the capsule wall, while the plasticizer enhances its flexibility and elasticity, preventing the capsule wall from becoming brittle and cracking, ultimately forming a sealed capsule that can encapsulate liquid contents.

Biocompatibility Advantages

Pharmaceutical-grade gelatin is derived from the hydrolysis of collagen protein. It has high compatibility with human tissues, is non-antigenic and non-irritating, and can be digested and absorbed by human digestive enzymes after oral administration, without causing a burden on the gastrointestinal tract, making it suitable for people who require long-term medication. Adaptation to Special Drug Formulations

For some poorly water-soluble, volatile oil-soluble drugs (such as vitamin E and fish oil extracts), the gelatin capsule shell of soft capsules can provide a sealed enclosure, preventing drug volatilization and loss, while also improving oral compliance.

III. Core Advantages and Industry Standards of Application

Compliance Assurance

The gelatin used in capsule production must comply with international standards such as USP (United States Pharmacopeia), EP (European Pharmacopoeia), and JP (Japanese Pharmacopoeia), and meet cGMP (Current Good Manufacturing Practice) requirements.  It must pass rigorous endotoxin, heavy metal, and microbial limit testing to ensure drug safety.

Strong Process Adaptability

The gelation temperature and viscosity of gelatin can be customized according to the production needs of pharmaceutical companies, adapting to automated capsule filling production lines and significantly improving production efficiency.