Softgel Manufacturing Process: Encapsulation, Drying and Inspection

Softgel manufacturing requires controlled formulation, precise encapsulation, gradual drying and strict inspection procedures. Modern softgel lines can produce over 100,000 capsules per hour, while pharmaceutical-grade operations usually control fill weight variation within ±3%, shell moisture around 5–8%, and storage stability for 24–36 months. The process combines gelatin science, mechanical engineering and quality testing to produce capsules with consistent appearance, strength and dosage accuracy.

Softgel production starts with preparing the gelatin shell material. The shell is usually made from gelatin, purified water and plasticizers such as glycerol or sorbitol. A typical shell mixture contains around 35–45% gelatin, while plasticizers are adjusted according to the required flexibility and final product characteristics. The gelatin mass is heated, mixed and filtered before entering the encapsulation system.

The quality of gelatin preparation affects the following manufacturing steps. If viscosity is too high, ribbon formation becomes difficult; if viscosity is too low, the shell may become weak after drying. Manufacturers often control gelatin temperature between 55°C and 65°C during processing to maintain suitable flow properties. Vacuum deaeration is also applied because removing trapped air reduces defects such as bubbles and uneven shell surfaces.

“A stable gelatin ribbon provides the foundation for consistent capsule formation. Small changes in temperature, viscosity or moisture content can influence sealing quality during encapsulation.”

The fill material is prepared at the same time as the shell. Softgels are commonly used for oil-based ingredients, vitamins, supplements and pharmaceutical compounds with low water solubility. The formulation process includes mixing active ingredients with carriers, antioxidants or suspension agents when needed.

Before filling, manufacturers measure several properties:

Parameter	Typical control range
Fill weight variation	Within approximately ±3%
Gelatin concentration	35–45%
Shell moisture after drying	5–8%
Drying time	12–48 hours

The encapsulation stage connects formulation preparation with capsule formation. Rotary die machines are widely used because they can produce large quantities with accurate dosing. During operation, two gelatin ribbons move through rotating dies while the fill material is injected between them. Pressure and temperature from the dies create the capsule shape and seal the two shell layers together.

Machine settings must remain stable throughout production. Die temperature, ribbon thickness, injection timing and machine speed are adjusted according to capsule size and formulation type. A production line running at 100,000 capsules per hour may process several million capsules within a single batch, so small equipment variations can affect a large quantity of product.

Encapsulation accuracy depends on maintaining stable machine conditions rather than increasing production speed alone. Manufacturers usually monitor capsule weight, sealing appearance and leakage rate during production to confirm that the process remains within approved limits.

After encapsulation, freshly produced softgels contain significant moisture and require drying. Newly formed gelatin shells may contain approximately 30–40% water, which must be reduced gradually. The purpose of drying is to create a shell with suitable flexibility, strength and long-term stability.

The first drying stage normally uses tumble dryers. Capsules rotate continuously while air circulation removes surface moisture and prevents capsules from sticking together. The second stage uses controlled drying rooms where temperature, airflow and humidity are maintained for longer periods.

Drying conditions are usually maintained around 20–25°C with relative humidity below 30% in many commercial facilities. The process may take 12–48 hours depending on capsule size, gelatin composition and fill material. Excessive drying speed can cause brittle shells, while insufficient drying may result in deformation or poor storage performance.

“Controlled moisture removal allows gelatin molecules to form a stable structure without damaging capsule flexibility.”

The drying process determines the physical properties that are later evaluated during inspection. Once capsules reach the target moisture range, they move to quality testing stations.

Inspection begins with visual checks. Operators or automated systems examine capsule shape, color consistency, surface condition and sealing areas. Modern vision systems can analyze thousands of capsules per minute and identify defects such as cracks, leakage marks, air bubbles and incomplete sealing.

Weight testing is performed to confirm dosage accuracy. For pharmaceutical products, sampling plans are commonly based on statistical standards. A batch containing millions of capsules may require hundreds of units for testing depending on regulatory requirements and production scale.

Common inspection items include:

• Capsule appearance and surface quality

• Average fill weight and weight variation

• Shell thickness and dimensions

• Leakage resistance

• Dissolution performance

• Active ingredient content

Dissolution testing evaluates how quickly the capsule shell breaks down under controlled conditions. Many softgel products are tested using simulated gastrointestinal environments, with results compared against approved specifications. Pharmaceutical manufacturers may perform these tests during development, production release and stability programs.

Stability testing provides information about how softgels perform during storage. Accelerated studies often use conditions such as 40°C temperature and 75% relative humidity for several months. Samples are checked for ingredient concentration, oxidation level, capsule appearance and mechanical properties.

For example, omega-3 softgels require careful oxidation monitoring because unsaturated oils are sensitive to oxygen exposure. Manufacturers may measure peroxide value and other oxidation indicators throughout storage evaluations. Proper formulation and packaging selection help maintain product quality over the expected shelf life.

Packaging follows inspection approval. Softgels are commonly packed in bottles, blister packs or foil-based materials depending on ingredient sensitivity. Products containing oxygen-sensitive oils often require stronger barrier packaging compared with more stable vitamin products.

Packaging environments are also controlled to reduce moisture exposure. Many commercial softgel products are designed for shelf lives of 24–36 months when stored under recommended conditions. The packaging process must protect capsules from humidity, light and temperature changes during transportation and storage.

Manufacturers developing or improving production systems often refer to resources such as the ProSafeNutra softgel guide to review process parameters, equipment considerations and quality control practices.

Quality management continues after packaging. Batch records, inspection results and process data are reviewed to confirm that each production run meets established requirements. GMP facilities introduced stricter digital monitoring systems after 2010, allowing manufacturers to record temperature, humidity and equipment performance throughout the manufacturing cycle.

A complete softgel process depends on the connection between material preparation, encapsulation control, drying management and inspection accuracy. Each stage uses measurable parameters, from gelatin concentration and moisture levels to capsule weight and dissolution results, to maintain consistent product performance across large-scale production.