Capsule shells - What you need to know about materials, safety & differences

Have you ever wondered what the capsule shells of food supplements are made of? Where do they come from and why does the choice of capsule shell make a crucial difference? In this blog post, we show you the different forms of capsule shells and look at the science behind them.

Why do we need capsules at all?

To put it simply, capsules protect the ingredients from harmful external influences. The oxygen in our air can interact with the molecules and oxidize them. If you want to try this out for yourself, all you have to do is leave a sliced apple out in the fresh air for a few hours. The brown spots that form are the result of oxidation.

In order to protect the valuable ingredients from the influence of oxygen and moisture, we pack them in capsules.

But then why don't we use tablets right away?

Capsules vs. tablets: What are the advantages?

Tablets certainly have their advantages - they are often cheaper to produce and easier for the manufacturer to handle. But for the consumer, they can be a tough nut to crack...literally! Large or sharp-edged tablets are a real challenge for many people to swallow

Capsules, on the other hand, slide down the throat rather smoothly. An advantage that should not be underestimated, especially with larger dosages or ingredients with a dubious taste.

Perhaps you have already smelled cod liver oil or tried barley grass powder - neither have a pleasant smell/taste and capsules are the much more pleasant alternative.

But there's more: Capsules are not only easier to swallow, they also protect sensitive ingredients such as vitamins, enzymes or probiotics from aggressive stomach acid. The active ingredients can thus enter the intestine undamaged and be optimally absorbed. They often have a much harder time with tablets.

Another plus point for capsules: Fewer unnecessary additives such as fillers, binders etc. are usually required for their production Capsules can therefore offer a "purer" composition .

Which capsule shells are available

Capsule shells can be roughly divided into two main categories: gel capsules (gelatin) and vegetarian capsules. There are several variations within these categories:

1. Hard gelatine capsules: These consist of two cylindrical parts that are pushed together. They are flexible and can be used for a variety of ingredients
2. Soft gelatin capsules: They are often used for liquid or oily ingredients and are made in one piece
3. HPMC capsules (hydroxypropyl methylcellulose): These plant-based capsules are an alternative to gelatine and offer numerous benefits, as we will see in a moment
4. Pullulan capsules: Made from a polysaccharide derived from starch, they are vegan like HPMC capsules and provide a good barrier against oxygen

HPMC - what's behind the abbreviation

Hydroxypropylmethylcellulose (HPMC) is a plant-based polymer that has a number of properties that make it the best choice for capsule shells. HPMC is derived from cellulose and offers several advantages over traditional gelatine capsules:

1. Vegan and allergen-free: HPMC is completely plant-based, making it a preferred choice for vegetarians, vegans and people with allergies
2. High stability: HPMC capsules are less likely to break down under different storage conditions. They are insensitive to temperature fluctuations and moisture
3. Gastro-resistant: HPMC can be formulated to be gastro-resistant, making it suitable for ingredients that are to be released in the intestine
4. Good bioavailability: These capsules enable effective release of the active ingredients, which increases bioavailability

What is Gellan?

Gellan is a special gelatine substitute that is used to produce stable and flexible capsule shells. It is obtained from natural raw materials and is often used in the food and pharmaceutical industries. However, HPMC often remains the superior choice as a plant-based and enteric-coated carrier.

Which capsule shells are vegan?

Vegetarian and vegan capsule shells are typically made from plant-based materials such as HPMC and pullulan . These offer similar functionality to gelatine, but without using animal products .

Gelatine is usually obtained from the bones or cartilage remains of cattle or pigs.

Gastro-resistant capsule shells - when are they useful?

Gastro-resistant capsulesare designed in such a way that they do not disintegrate in the stomach but are dissolved in the intestine. This is particularly advantageous for ingredients that are destroyed or impaired in their effect by stomach acid. This type of capsule shell can be used to ensure that sensitive nutrients or medications are only released where they are most needed.

Without the protective PEG coating,z.Bthe ingredients of our QBIOTICS would be released too early . The bacteriumBacillus subtilis it contains only develops its positive effect in the intestine. In the stomach, the acid would kill the bacterium.

If you want to find out more about this topic, you can find more information in the article on absorption pathways .

Harmful capsule shells? You should pay attention to this

Gelatine from China - risks and scandals

In 2019, the Frankfurter Rundschau reported on a capsule scandal from China . There, gelatine containing harmful substances was produced from leather waste that was not suitable for consumption. Residues of heavy metals and other potentially carcinogenic substances were found in this gelatine. This gelatine was sold for the production of medicines. When the inspectors tried to inspect the accused company, the owner burned it down.

Luckily, scandals like this are rare, but they show how important regular inspections are. At MOLEQLAR, we test every batch of raw materials for purity and heavy metal residues , among other things. This allows us to ensure that we always meet the highest quality standards. If you want to find out more, you can view the individual documents on ourCertificates page.

Are HPMC capsules dangerous?

For humans, the consumption of HPMC is considered harmless . For us, HPMC is a water-soluble dietary fiberthat is excreted undigested. This would also be reviewed by several authorities, such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the European Food Safety Authority (EFSA). The former has set an "unspecified" acceptable daily intake (ADI) for the use of HPMC in food. This means that, based on the available toxicity data, there are no health concerns at current use and exposure levels.

EFSA also concluded that no numerical ADI is required for HPMC and that there are no safety concerns at current uses and intake levels. Somestudies in animals even showed good tolerability of HPMC at very high doses of up to 7,500 mg/kg body weight per day.

So we can summarize that HPMC capsules not only offer some benefits, they are also safe .

Did you know

HPMC can be found in many foods. HPMC can be found behind the number E464. In baked goods, HPMC improves texture, creaminess and shelf life. It prevents drying out and is often used in frostings, spreads and gluten-free baked goods. The versatile substance is also used as a gelling agent and stabilizer in dairy products such as yoghurts or cream cheese preparations.

Dressings, sauces and dips would often be bland and watery without HPMC. Here it helps to achieve the right creaminess and consistency. The same applies to processed meat products such as sausages, in which it serves as an emulsifier and binding agent.

Why we rely on HPMC casings at MOLEQLAR

We at MOLEQLAR are committed to superior quality standards , not only for the ingredients but also for the capsule shells. This is why we choose ultra-pure HPMC capsules. They are completely plant-based, offer high stability and are excellent at retaining moisture. All these properties qualify HPMC as the ideal material for food supplements of the highest quality. Manufacturer certificates for the capsules also ensure that they are free from carrageenan or PEG.

Conclusion: Making the right choice for capsule shells

When it comes to choosing the right capsule shell for food supplements, HPMC capsules are second to none due to their plant-based origin, stability and versatility. Not only are they a sustainable alternative to traditional gelatin capsules, but they also offer specific benefits such as gastro-resistant and improved bioavailability . Therefore, it is worth paying particular attention to the use of high-purity HPMC when choosing supplements to ensure that you get a product that is both effective and ethical.

Transparent manufacturers also state whether their capsules are free from harmful additives. After all, not all HPMC is the same.