Two-piece hard capsules are made from one of two materials: gelatin, the traditional animal-derived shell, or HPMC (hydroxypropyl methylcellulose), a plant-based shell. Both look almost the same on the shelf, but they behave differently with moisture, heat and certain ingredients. Here is how to choose.
Choose gelatin for most standard powders when cost and fast dissolution matter. Choose HPMC when the product must be vegetarian, vegan, halal or kosher-friendly, or when the fill is sensitive to moisture.
What is the difference?
Gelatin is a protein obtained from collagen (usually bovine or porcine). HPMC is made from cellulose, the structural fibre of plants. Gelatin shells hold more water and stay flexible because of it; HPMC shells hold much less water and stay flexible even when very dry.
| Gelatin capsules | HPMC capsules | |
|---|---|---|
| Source | Animal collagen | Plant cellulose |
| Typical shell moisture | About 13–16% | About 3–7% |
| Vegetarian / vegan | No | Yes |
| Moisture-sensitive fills | Less suitable: the shell can pass water to the fill | Better choice |
| Behaviour when very dry | Can become brittle | Stays flexible |
| Reaction with aldehydes | Can cross-link and dissolve more slowly | Not affected in the same way |
| Dissolution | Fast in the stomach | Slightly slower start; depends on the grade |
| Cost | Lower | Higher |
When gelatin capsules are the better choice
- Standard vitamins, minerals, herbal powders and generic medicines without special moisture needs.
- High-volume products where shell cost matters.
- Products where fast, predictable dissolution is important.
Gelatin also has a very low oxygen permeability, which helps protect some oxidation-sensitive ingredients.
See our empty hard gelatin capsules →
When HPMC capsules are the better choice
- Vegetarian, vegan, halal or kosher-friendly products, where animal-derived gelatin is not acceptable.
- Hygroscopic (moisture-loving) fills such as some probiotics, enzymes and effervescent powders.
- Ingredients that react with gelatin, for example those containing aldehydes.
- Products stored or shipped in very dry or very warm conditions.
Storage tips for both
Keep empty capsules in their sealed packing, at roughly 15–25 °C and moderate humidity, away from direct sunlight and away from walls and floors. Gelatin capsules are more sensitive: too much humidity makes them soft and sticky, too little makes them brittle. HPMC capsules tolerate dry conditions much better.
Frequently asked questions
Are HPMC capsules halal?
HPMC is plant-derived, so it is generally accepted for halal and kosher-friendly products. Ask your supplier for the relevant certificate for the specific capsules you buy.
Do HPMC capsules dissolve as fast as gelatin?
They start to dissolve slightly more slowly, but standard HPMC capsules still release their contents well within normal immediate-release timeframes. Your formulator should confirm this for your product.
Can I switch an existing product from gelatin to HPMC?
Often yes, but the change should be tested for filling performance, stability and dissolution before launch.
Need empty gelatin or HPMC capsules?
Soft Enterprises supplies empty hard gelatin capsules and HPMC capsule shells in bulk. Tell us your size, colour and quantity.
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