For dietary supplement brands, the delivery format is just as critical as the active ingredients. While gummies and softgels are trending, the traditional hard gelatin capsule remains the “gold standard” for the pharmaceutical and nutraceutical industries. It offers a balance of cost-effectiveness, durability, and consumer familiarity.
But as a brand owner or product developer, you need to know exactly what goes into your product. Whether you are addressing consumer concerns about ingredients or evaluating raw material quality for your next production run, understanding the composition is key.
At its most fundamental level, a gelatin capsule consists of Gelatin (derived from the hydrolysis of animal collagen) and Purified Water. Depending on the type of capsule (Hard Shell vs. Softgel) and the specific branding requirements, the formulation also includes Plasticizers (like glycerin) for flexibility, Colorants, and sometimes Preservatives.
While the ingredient list seems simple, the quality of these raw materials dictates the capsule’s performance—affecting everything from shelf-life stability to how fast it dissolves in the customer’s stomach.
Why Gelatin Remains the Industry Leader
Despite the rise of vegetarian (HPMC) alternatives, gelatin capsules continue to dominate the market for several key manufacturing reasons:
Superior Oxygen Barrier
Gelatin protects sensitive ingredients (like Vitamin C or probiotics) from oxidation better than most plant-based alternatives, extending shelf life.
Cost Efficiency
For brands looking to lower their Cost of Goods Sold (COGS), gelatin remains the most economical option available for mass production.
Manufacturing Reliability
Gelatin creates a robust shell that withstands the high mechanical stress of high-speed filling machines, reducing breakage and waste.
In this guide, we will break down the exact chemical composition of gelatin capsules, the differences between hard and soft shell “recipes,” and the manufacturing process we use at Gensei to ensure every capsule meets safety and quality standards.
What Exactly is Inside a Gelatin Capsule?
While the finished product looks like a simple, uniform shell, the chemical composition is a precise balance of ingredients designed to maintain structural integrity while dissolving rapidly in the stomach.
For any brand owner, understanding this composition is crucial when vetting a capsule supplement manufacturer. A reliable partner will be transparent about the sourcing of these raw materials to ensure your final product meets safety and quality standards.
Here is the breakdown of the raw materials we use in the manufacturing process.
The Base Material: Animal-Derived Gelatin
The primary ingredient is Gelatin, a translucent, colorless, and flavorless food ingredient derived from collagen. Collagen is the main structural protein found in animal connective tissue.
To create the gelatin used in capsules, raw collagen undergoes a process called partial hydrolysis. This breaks down the tough collagen fibers into a soluble protein mixture that gels when cooled.
For manufacturers and brand owners, the source of the gelatin is the most critical decision, as it affects cost, marketing claims, and regulatory compliance:
- Bovine (Cow): The most common source for hard capsules. It is cost-effective and widely accepted. Note: At Gensei, we strictly use BSE/TSE-free bovine gelatin (free from Mad Cow Disease agents) to ensure global safety compliance.
- Porcine (Pig): Often used in softgels due to its specific plasticity options. However, it is not suitable for Halal or Kosher-certified products.
- Piscine (Fish): A premium option for “marine collagen” supplements. It is popular in the beauty industry but comes with a higher raw material cost.
Purified Water (The Structural Stabilizer)
It might surprise you, but water is a structural component of the capsule, not just a solvent used during mixing.
During the “dipping” phase, the gelatin solution must be highly liquid to coat the mold pins evenly.
After drying, the capsule locks in a specific moisture content to maintain structural integrity.
The Brittleness Risk:
The capsule shell loses flexibility. It may shatter or crack during bottling, shipping, or when consumers press them out of blister packs.
The Stability Risk:
The capsule becomes too soft and loses shape. Excess moisture also creates a breeding ground for microbial growth and mold.
Plasticizers (For Flexibility)
Plasticizers are additives that lower the glass transition temperature of the gelatin, making the shell pliable rather than brittle.
- In Hard Capsules: Very low amounts of plasticizers are used. The water content acts as the primary natural plasticizer.
- In Softgels: Plasticizers are essential. Ingredients like Glycerin (Glycerol) or Sorbitol are added in significant ratios (sometimes up to 30%). This is what gives softgels their signature “squishy” feel and prevents them from leaking or cracking.
Additives & Processing Aids
To turn a clear gelatin shell into a branded product, we introduce specific additives.
- Colorants: We use both synthetic dyes (for vibrant, consistent brand colors) and natural colorants (like chlorophyll or beetroot extract) depending on client requirements.
- Opacifiers: To protect light-sensitive ingredients (like Riboflavin or Omega-3s), we make the shell opaque. Historically, Titanium Dioxide (TiO2) was the standard. However, due to changing EU regulations, Gensei now offers high-quality TiO2-free alternatives using calcium carbonate or other minerals.
- Preservatives: While hard capsules rarely need preservatives due to their low water activity, parabens are sometimes used in softgels to prevent fungal growth, though the trend is moving toward preservative-free clean labels.
The Secret to Durability: Bloom Strength
The quality of a capsule isn’t just about ingredients—it’s about rigidity. At Gensei, we utilize high-bloom gelatin (200–250 Bloom). This ensures the capsule snaps closed securely and resists denting during high-speed filling, unlike lower-grade alternatives which may deform.
Hard Shell vs. Softgel: How the “Recipe” Changes
While both formats start with the same base (Gelatin + Water), the final “recipe” varies significantly depending on the delivery system you choose. The key difference lies in the ratio of plasticizers.
Understanding this distinction helps you choose the right format for your specific supplement formulation.
Hard Gelatin Capsules (HGC)
This is the classic two-piece capsule (Body & Cap) used for powders and pellets.
- The Formula: High Gelatin, Low Plasticizer.
- Plasticizer Ratio: Typically less than 5%.
- Why? Hard capsules rely on moisture (water) for their flexibility. We need them to be rigid enough to withstand the mechanical force of the joining process (where the cap snaps onto the body). If we added too much glycerin, the capsule would become sticky and fail in the filling machine.
- Best For: Dry ingredients (Herbal powders, Vitamins, Minerals, Amino Acids).
Soft Gelatin Capsules (Softgels)
This is a one-piece, hermetically sealed shell used primarily for oils and liquid suspensions.
- The Formula: High Plasticizer Content.
- Plasticizer Ratio: Typically 20% to 30% (by weight of the dry shell).
- Why? Because the fill material is liquid, the shell must be flexible and elastic to expand slightly without cracking. We add significant amounts of Glycerin (Glycerol) or Sorbitol to achieve this rubbery texture.
- Best For: Oils (Fish Oil, Vitamin D3, Vitamin E) or fat-soluble nutrients that need improved bioavailability.
Comparison Table: The Ingredient Ratios
Use this table to quickly compare the chemical makeup of our two primary capsule offerings.
| Component | Hard Gelatin Capsule (HGC) | Soft Gelatin Capsule (SGC) |
| Gelatin | ~80% – 85% | ~40% – 50% |
| Plasticizer | < 5% (Minimal) | 20% – 30% (High) |
| Moisture (Finished) | 13% – 16% | 6% – 10% |
| Wall Thickness | ~100 µm (Thinner) | ~800 µm (Thicker) |
| Primary Use | Dry Powders / Pellets | Liquids / Pastes |
🌱Gensei Formulation Tip:
If you are formulating a “Liquid-Filled Hard Capsule” (LiCaps), we adjust the banding solution to ensure the liquid doesn’t leak from the two-piece join. This is a specialized service we offer for brands who want the look of a hard capsule but the bioavailability of a liquid.
The Manufacturing Process: From Gel Mass to Finished Capsule
Knowing what are supplement capsules made of is only half the battle. To produce a shell that runs smoothly on your filling machines and dissolves consistently in the consumer’s stomach, the manufacturing process must be executed with surgical precision.
The Gensei Manufacturing Protocol
From raw gel mass to finished dosage form in 4 precision steps.
Melting gelatin/HPMC at 70°C, vacuum de-aerating to remove bubbles, and adding custom colorants.
Stainless steel pins dip into the solution. Spinning ensures uniform wall thickness on Cap and Body.
Controlled kilns slowly reduce moisture from 70% to the target 13-16% to prevent case hardening.
Shells are stripped, trimmed to length, and mechanically joined (Pre-Lock) before final inspection.
At Gensei, our production lines operate in cleanroom environments (ISO Class 8 or higher) to prevent contamination. If you have ever wondered how is capsule supplement manufacturing actually performed on the factory floor, it follows a rigorous four-step “Dip Molding” process.
Step 1: Gel Preparation (Melting & Blending)
The process begins in the “Kitchen.” We mix the raw gelatin (or HPMC) with hot purified water (approx. 70°C to 80°C) in stainless steel melting tanks.
- Vacuum De-aeration: We apply a vacuum to remove air bubbles. Even microscopic bubbles can cause weak spots or holes in the final capsule.
- Coloring: Dyes and opacifiers are added here. This is where your custom brand color is defined.
- Viscosity Check: The gel mass must be thick enough to stick to the mold, but thin enough to spread evenly.
Step 2: The Dipping Process
Once the gel is ready, it is fed into the hopper of the capsule machine.
- The Pins: Thousands of stainless steel pins—arranged on bars—are dipped into the gelatin solution.
- Body vs. Cap: There are two separate lines running simultaneously: one set of pins is slightly smaller (for the capsule Body), and one set is slightly larger (for the capsule Cap).
- Spinning: Immediately after dipping, the pin bars rotate. This ensures the gelatin distributes evenly over the pin to create a uniform wall thickness.
Step 3: Drying (The Critical Phase)
The coated pins pass through a series of drying kilns. This is the most delicate stage. Large volumes of filtered, temperature-controlled air are blown over the pins.
- We slowly reduce the moisture content from the initial ~70% down to the target 13–16%.
- Quality Control: If we dry them too fast, the shell warps (“case hardening”). If we dry them too slow, production stalls.
Step 4: Stripping, Trimming, and Joining
Once dry, the shells are stripped off the steel pins by bronze jaws.
- Trimming: The rough edges are cut to the exact length (creating the clean edge you see on a finished capsule).
- Joining: The Cap and Body are pushed together in a “Pre-Lock” position.
- Ejection: The finished empty capsules are ejected, inspected, and packed into moisture-proof liners, ready to be shipped to your filling facility—or moved to Gensei’s internal filling department for your OEM order.
Gelatin vs. Vegetarian (HPMC): Which Should You Choose?
As a brand owner, one of the most critical decisions in product development is the choice between Gelatin vs. Vegetarian (HPMC) Capsules.
At Gensei, we manufacture both formats. The “right” choice depends entirely on your target audience and the chemical nature of your ingredients.
Gelatin Capsules
The Industry Standard- Cost-Effective: Significantly cheaper to produce than HPMC/Veggie options.
- Oxygen Barrier: Superior protection for sensitive ingredients like Vitamin C.
- Familiarity: Standard “glossy” look and feel consumers expect.
- Note: Not suitable for Vegan or Kosher certifications.
HPMC Capsules
Vegetarian & Vegan Friendly- Global Appeal: Suitable for Vegan, Kosher, and Halal markets.
- High Stability: Low moisture (4-6%) means they won’t crack when filled with hygroscopic powders.
- Clean Label: Made from pine wood pulp cellulose.
- Note: Higher raw material cost.
Why Choose Gensei for Your Capsule Manufacturing?
Understanding what a capsule is made of is the first step. Finding a partner who can consistently manufacture them to pharmaceutical standards is the next.
Gensei is not just a manufacturer; we are your strategic partner in the dietary supplement supply chain. Whether you need hard shells, softgels, or a completely custom formulation, we provide the infrastructure to scale your brand.
Low MOQ & Flexibility
Most contract manufacturers require massive minimum orders (often 300,000+ capsules). Gensei supports growing brands with Low MOQ (Minimum Order Quantity) options, allowing you to test new formulas without tying up capital in inventory.
Custom Formulation Services
Don’t settle for “off-the-shelf” white pills.
- Custom Colors: Match the capsule shell to your brand logo (Pantone matching available).
- Branding: We offer axial and radial printing directly on the capsule (e.g., printing your logo or dosage strength).
- Size Variety: From Size 000 to Size 5.
End-to-End R&D Support
Have a difficult ingredient? Our R&D team specializes in solving complex challenges, such as:
- Masking the taste of bitter herbs.
- Stabilizing liquid-filled hard capsules.
- Creating “Clean Label” formulas free from magnesium stearate or silicon dioxide.
FAQs
Conclusion
A gelatin capsule is more than just a container; it is a sophisticated delivery system engineered from collagen, water, and precision manufacturing. By choosing high-quality ingredients and a manufacturer who prioritizes strict quality control, you ensure your customers get a safe, effective product every time.
- If you want to learn more about capsule supplements, or if you are unsure whether your current formula requires a hard shell, softgel, or HPMC solution, Gensei is here to help. We believe that an informed client is a successful client.
- Ready to launch your next supplement? Contact Gensei today for a free consultation and quote. Let us handle the technical details so you can focus on growing your brand.
references
- Gelatin（source link: https://en.wikipedia.org/wiki/Gelatin)
- we strictly use BSE/TSE-free bovine gelatin.（source link: FDA Announces Final Rule on Bovine Spongiform Encephalopathy.)
- a hard gelatin capsule must retain a moisture content of 13% to 16%.（source link: National Center for Biotechnology Information (NCBI)
- The European Commission has just banned titanium dioxide/Ti02 (also known as E171) as a food additive.（source link: https://ec.europa.eu/newsroom/sante/items/732079/en
