Prolonged release: maximising the duration of action of supplements

What is meant by ‘sustained release’?

A formulation technology for slow, continuous release of active ingredients

Sustained release (SR) is a technology used in the formulation of food supplements, which allows the active ingredients to be released slowly and continuously into the body.

This technology is particularly useful for providing continuous support to the body in the event of fatigue or stress.

Unlike a traditional immediate-release form, which is rapidly absorbed, sustained-release food supplements are designed to have an effect that lasts several hours.

Quite often, this type of formulation combines a delayed release (after passing through the stomach) with a gradual release of the active ingredients over time.

A galenic formulation that modifies the diffusion of active ingredients

Prolonged release is made possible by specific galenic formulations, i.e. formulation processes designed for this purpose.

For food supplements to be taken orally, this may involve:

• polymeric coating, which coats the active ingredients with a protective film that dissolves slowly in the digestive tract, delaying their release;
• encapsulation, which encloses the active ingredients in small capsules (often lipidic or gelatinous) that gradually break down;
• integration of the active ingredients in a plant matrix (fibres) or lipid matrix (fats), which regulates their release at the rate of digestion;
• the addition of specific molecules that bind to the desired substance to slow down its absorption.

These devices are able to resist degradation by gastric acid in the stomach, releasing the nutrients as digestion proceeds.

What is the advantage of sustained release?

Sustained-release formulations are particularly useful for formulas containing water-soluble substances, which have a very short half-life and are rapidly eliminated in the urine (1).

This is particularly true of certain vitamins and magnesium.

By slowing down the release of active ingredients, we improve their overall absorption and therefore their bioavailability.

We also limit plasma peaks, which result in a sudden high concentration of active ingredients in the blood: present in excess over a short period, these active ingredients are largely eliminated before they are absorbed.

In this way, a more stable blood concentration of the desired substances is maintained, resulting in longer-lasting efficacy over time.

The body can therefore 'take its time', and use what it needs when it needs it.

Sustained-release multivitamins for continuous action throughout the day

Some multivitamin formulas use sustained-release technology to ensure a constant supply of micronutrients throughout the day.

This process ensures an optimal intake of water-soluble vitamins and minerals – such as vitamins B and C – which are rapidly eliminated by the body when absorbed in a conventional immediate-release form.

By spreading out their release, these multivitamins optimise the body's absorption of nutrients. As well as improving bioavailability, this reduces the risk of unnecessary short-term overloads.

Better still, they support the body on a more regular basis, which is particularly useful in cases of persistent fatigue, chronic stress or a lack of vitamins and minerals that the body cannot store for later.

Products based on this principle include some very comprehensive supplements. They contain different nutrients and natural extracts selected for their synergistic actions.

These sustained-release multivitamins are particularly suitable for people who want to support their metabolism, immunity or energy levels on a regular basis, without having to take them several times a day.

Some can be taken as a single dose a day.

• Discover the Daily 1 food supplement and its timed-release coating, which ensures that the nutrients are released gradually for better assimilation.

Others need to be taken twice a day.

• Discover the Daily 2 Timed Release food supplement, which provides all its micronutrients throughout the day, to cover a maximum of needs.

What are the alternatives for optimising the effectiveness of food supplements?

Liposomes: microcapsules inspired by cell membranes

Not all formulation strategies are based solely on sustained release. Some may focus on other techniques for diffusing or releasing active ingredients.

Liposomal forms, for example, use liposomes, tiny vesicles with a double phospholipid layer that trap the active ingredient at the centre or in the membrane.

This structure is similar to that of our cell membranes. It has the advantage of protecting the nutrients from gastric juices.

What's more, liposomes fuse easily with the cells in the intestinal walls, which increases the bioavailability of the active ingredients they encapsulate (2).

Liposomes are often used to optimise vitamin C absorption.

• Discover the Liposomal Vitamin C dietary supplement, which uses Liposomal Delivery™ technology to increase the bioavailability of vitamin C compared with conventional forms.

Gastro-resistant capsules for delayed release of probiotics

Probiotics taken orally are relatively fragile and can be destroyed by gastric acidity as they pass through the stomach (3). However, their preferred site of action is the colon.

To ensure that they reach the intestinal microbiota intact, food supplement manufacturers use gastro-resistant capsules.

These are not sensitive to gastric acid and only dissolve once they reach the intestines, for optimum effectiveness.

• Discover Probio Forte or Full Spectrum Probiotic food supplements packaged in gastro-resistant capsules.

Extracts selected for their high bioavailability

Some substances are more effective when taken in a chemical form that is better absorbed by the human body.

This is the case, for example, with magnesium L threonate. Its chemical structure enables it to cross the blood-brain barrier and reach the brain directly (4).

As a result, it offers a more precise and longer-lasting effect on cognitive health, with magnesium helping to reduce fatigue and promote normal functioning of the nervous system and psychological function.

It is often found in food supplements targeting cognitive health and muscle, bone and heart function.

• Discover Magtein Magnesium L-Threonate food supplement.