Pullulan capsules represent an emerging plant-based capsule type that has demonstrated broad application prospects in the pharmaceutical and health supplement sectors in recent years.
This article will introduce their characteristics, size specifications, production processes, and core manufacturing equipment, helping you better evaluate and select a pullulan capsule manufacturing solution that best aligns with your production requirements.
What is a Pullulan Capsule?
Pullulan capsules are transparent, colorless, and smooth-surfaced plant-based capsules with a glossy finish. They primarily consist of 85% to 90% pullulan, with the remaining 10% to 15% composed of purified water, tamarind gum, and xanthan gum.
Pullulan is a natural polysaccharide polymer obtained through the fermentation of corn starch. It features excellent film-forming properties, flexibility, and mechanical strength. And unlike most polysaccharides, pullulan possesses good water solubility which makes it easier to process and form during capsule preparation.
Pullulan capsules align with market trends for clean labels and plant-based ingredients, and it can offer distinct advantages in maintaining drug stability and ensuring comfortable administration for your production applications.
Features of Pullulan Capsules
100% Vegan
As a vegetable capsule, it contains no animal-derived ingredients and is free from common allergens such as dairy, peanuts, and tree nuts at the same time. It is suitable for diverse consumer groups.
Pure Natural Ingredients
It is made from naturally fermented pullulan, free from genetically modified ingredients, which can meet consumer demand for natural, safe, and non-animal-derived products.
High Probiotic Compatibility
The capsule itself possesses prebiotic potential, supporting the growth and activity of beneficial gut bacteria (such as Bifidobacteria and Lactobacillus), providing added functional value for developing gut health products.
Safety and Tolerability
In toxicology, its No observed adverse effect level (NOAEL) reaches 7,900 mg/kg body weight daily—far exceeding typical intake levels which can guarantee reliable and safe intake.
High Bioavailability
The capsule dissolves rapidly within 15 minutes, enabling swift release of active ingredients to enhance bioavailability and product absorption efficiency.
Superior Oxygen Barrier
The oxygen permeability is approximately 1/300th that of hydroxypropyl methylcellulose capsules and 1/8th that of gelatin capsules. This effectively protects active ingredients prone to oxidation (such as probiotics and polyphenols) and significantly extends the product’s shelf life.
Broad Compatibility
Pullulan capsules can be filled with diverse materials including powders, granules, pellets, tablets, and dry herbs. This versatility enables you to address a wide range of formulations and dosage forms with a single capsule solution.
How to Produce Pullulan Capsules
The production of pullulan capsules primarily involves two manufacturing processes: the traditional dip-coating method and the freeze-setting method. Each process is suited for different production scales and types. You may select the appropriate method based on your equipment configuration and output requirements.
Traditional Glue-Coating Method
- First, dissolve pullulan in purified water and add surfactant, coagulation aid and others in specified proportions to prepare a film-forming solution with appropriate viscosity and flowability.
- Then stir uniformly at approximately 90°C and perform vacuum degassing to ensure the glue solution is pure and bubble-free.
- Using automated dipping equipment to repeatedly immerse the molds into the solution to form the gelatin film.
- The formed capsules are dried at 25–45°C, precisely controlling moisture content between 10%–14% to ensure mechanical strength and stability of the capsule shell.
This production method offers strong compatibility. If you already have a gelatin capsule production line, you can often produce pullulan capsules by adjusting only a few key parameters.
Water Freezing Setting Method
- First, add pullulan into hot water in the specified ratio, stir thoroughly to eliminate bubbles, then let stand at approximately 20°C to maintain temperature;
- Control mold temperature between -40°C and 0°C, dip directly without adding additional gelling agents;
- According to the principle that water in the solution freezes below 0°C, the pullulan film rapidly sets on the mold surface and stable film formation by controlling the curing air temperature.
Pullulan capsules produced via this process exhibit uniform film formation and excellent light transmission while significantly reducing additive usage, particularly suitable for pure natural, additive-free applications.
Inspection
Formed pullulan capsules undergo polishing and cutting. Then they must pass the inspection, which includes capsule integrity, dimensional and weight variations, as well as chemical and microbiological analysis.
Pullulan Capsule Production Equipment
Pullulan Solution Preparation Machine
This equipment’s inner tank is constructed from 316L stainless steel, meeting GMP requirements for pharmaceutical production. It typically incorporates heating, stirring, filtration, and vacuum defoaming systems. Some models are also paired with low-temperature insulation capabilities to maintain prepared solutions between 45–65°C to prevent solidification.
Pullulan Dedicated Coating Machine
Pullulan dedicated coating machine adopts a servo control system for precise speed and angle regulation which ensures uniform thickness and consistent transparency for each capsule shell. In terms of production capacity, the standard model can manufacture 60,000 to 80,000 capsule shells per hour. In addition, the equipment supports rapid mold changeovers and accommodates the production of pullulan capsules in multiple specifications.
Pullulan Low-Temperature Setting Machine
This equipment employs a circulating cold air system and mold zone temperature control technology and its temperature control reach accuracy of ±2°C. Setting within the -40°C to 0°C range enables instantaneous gel film solidification and shaping without requiring gel-forming agents.
Compared to traditional dip-drying methods, low-temperature shaping improves efficiency by approximately 40% and increases product yield by 15–20%. However, costs are slightly higher, being 2–3 times that of conventional dip-drying machines.
Pullulan Capsule Shell Trimming Equipment
Common types include capsule shell cutting machines and capsule shell polishing machines, which are used to remove burrs, adjust capsule shell length, and effectively enhance surface gloss.
Capsule Sorting Machine
This equipment integrates visual inspection and weight detection systems to automatically identify defects such as cracks, bubbles, uneven wall thickness, and deformation. With detection accuracy reaching ±0.02mm and a rejection rate exceeding 99.5%, it significantly enhances batch consistency.
Automatic Capsule Filling Machine
Equipped with a vacuum split-type feeding system and servo-driven metering discs, this machine achieves filling accuracy within ±1.5%. And the standard one delivers an hourly output of 30,000–40,000 capsules.
The filling machine handles various forms including powders, granules, and pellets, meeting your production needs for functional health supplements, probiotics, pharmaceuticals, and other products.
How to Choose the Right Pullulan Capsules
Target Audience
If your product primarily targets vegans, halal/kosher consumers, or individuals sensitive to animal proteins and common allergens, pullulan capsules are the ideal choice. This is because they are completely free of animal-derived ingredients and common allergens like dairy, nuts, and peanuts. And they significantly increase your product’s market appeal through clean labeling.
Material Properties
If the product is susceptible to oxidation during shelf life or transportation—such as probiotics, antioxidants, or polyphenolic pharmaceuticals—Pullulan capsules are more suitable for you. They significantly enhance the stability of active ingredients, reducing risks of discoloration or potency loss.
Besides, the pullulan capsules exhibit excellent adaptability to heat and humidity and feature resisting deformation or sticking. This makes them also suitable for filling heat-sensitive or low-moisture materials.
Size
Capsule size impacts dosage control and consumer experience. All two-piece pullulan hard capsules adhere to international standardized specifications, where larger numbers indicate smaller capsule sizes. Common pullulan capsule shell sizes include 00, 0, 1, and 2.
For example, the larger 00 size is well-suited for high-dose formulations like herbal extracts and amino acids, while size 0 is typically used for packaging vitamins, health supplements, and similar substances.
Conclusion
Pullulan capsules have become an important choice for modern pharmaceutical and health supplement formulations due to their pure plant origin, exceptional oxygen barrier properties, and broad product compatibility. No matter targeting vegan consumers, requiring high-barrier protection for functional ingredients, or aligning with clean label market trends, they provide reliable technical solutions for you.
If you seek to further evaluate the feasibility of pullulan capsules for your specific product or require customized production solutions, let us provide you with professional and dependable solutions.
FAQ
What are pullulan capsules commonly used for?
Pullulan capsules are suitable for filling powders, granules, pellets, tablets, and dried herbal ingredients such as aspirin, vitamin C, Chinese herbal extracts, and cephalosporin antibiotics. Due to their inherently high moisture content, they are not recommended for filling highly hygroscopic or high-oil-content substances, as this may compromise the structural integrity and sealing performance of the capsule shells.
What are the disadvantages of pullulan capsules?
Compared to traditional gelatin or HPMC capsules, pullulan capsules need higher raw material and processing costs. And their solution film-forming process demands stringent temperature, humidity, and cleanliness requirements, imposing stricter precision demands on production equipment and process control.
If you have specific budget constraints regarding large-scale production costs or capacity, evaluate the overall economic viability of pullulan versus HPMC capsules based on project characteristics.
How to Store Pullulan Capsules?
We recommend the following storage conditions:
Store at temperatures between 15°C and 25°C with relative humidity between 45% and 65%. Avoid direct sunlight, proximity to heat sources, or high-humidity environments to prevent capsule shell deformation, brittleness, or sticking.
For long-term storage, it is advised to use sealed packaging or nitrogen-flushed packaging to effectively reduce the impact of oxidation and humidity fluctuations on product performance, ensuring capsules remain in optimal condition prior to filling.
