Introduction to Film Coatings in Nutraceuticals

Film Coatings in Nutraceuticals:
Enhancing Functionality, Protection, and Appeal

Film coatings are thin, uniform layers applied to the surface of nutraceutical tablets or granules. While often perceived as cosmetic, they serve a broad range of functional and technological purposes – from taste masking and swallowability to protection against moisture, light, and oxidation. Coating agents can also be used to control release profiles, enabling enteric protection or sustained delivery of sensitive bioactives.

In the nutraceutical space, where consumer expectations for clean-label, natural origin, and aesthetics intersect with manufacturing and stability demands, film coatings play a particularly strategic role. As highlighted in the PharmaExcipients overview on pharmaceutical film coatings, coating systems are evolving from purely pharmaceutical applications to more versatile, health-focused applications that balance performance and perception.

Why Use Film Coatings in Nutraceuticals?

Film coatings play a crucial role in enhancing the performance, stability, and appeal of nutraceutical tablets. One of their primary functions is to mask unpleasant tastes and odors – particularly important when working with challenging ingredients like herbal extracts, minerals, or amino acids. Coatings also improve swallowability, which is especially beneficial for larger tablets or products intended for children and the elderly.

Beyond sensory improvements, film coatings offer physical protection by shielding tablets from moisture and light, thereby extending shelf life and maintaining ingredient stability. They also help reduce dust and create smoother tablet surfaces, which not only enhance appearance but also improve manufacturing efficiency.

From a marketing standpoint, coatings enable brand differentiation through customizable color-coding and aesthetic enhancements. Moreover, functional coatings can be engineered to provide enteric protection or support modified-release profiles, helping tailor the delivery of active ingredients to specific physiological needs.

Categories of Coating Systems in Nutraceuticals

1. Aesthetic and Protective Film Coatings

These coatings focus on visual enhancement, physical protection, and palatability.

• • Polymers used:
    • Hydroxypropyl methylcellulose (HPMC)
    • Hypromellose (various grades)
    • Polyvinyl alcohol (PVA)
    • Natural polymers such as pullulan or shellac (for natural-positioned brands)
  • Plasticizers:
    • Polyethylene glycol (PEG)
    • Triethyl citrate
    • Glycerin
  • Colorants:
    • Iron oxides, titanium dioxide (not longer usable in EU for nutraceutical coatings), natural pigments (e.g., spirulina, beetroot)
    • Clean-label systems increasingly use natural color blends
  • Commercial examples:

    • BonuLac® or NutraPolish® Organic (Biogrund)

    • Sepifilm™ (Seppic)

    • ReadiLYCOAT® XC (Roquette)
  • Applications:
    • Improve tablet durability and reduce friability
    • Enhance product appearance
    • Mask unpleasant tastes or odors
    • Reduce powdery feel in chewables

2. Enteric Coatings

Designed to prevent tablet disintegration in the acidic environment of the stomach, releasing actives only in the more neutral pH of the intestine.

• • Use cases:
    • Protect acid-sensitive ingredients (e.g., probiotics, enzymes, vitamins like B12)
    • Reduce gastric irritation from certain botanicals or minerals
    • Enable targeted intestinal absorption
  • Polymers used:
    • Methacrylic acid copolymers (e.g., Eudragit® L/S)
    • Cellulose acetate phthalate (CAP)
    • Hydroxypropyl methylcellulose phthalate (HPMCP)
    • Natural alternatives (e.g., alginates, shellac)
  • Challenges:
    • Often require organic solvents or specialized aqueous dispersion systems
    • May increase processing time and cost

3. Sustained / Controlled-Release Coatings

These coatings are used to slow down the release of actives over time, allowing once-daily dosing or prolonged effect.

• • Use cases:
    • Energy supplements
    • Sleeping aids (e.g., melatonin SR)
    • Adaptogen delivery (e.g., Rhodiola, Ashwagandha)
    • Blood sugar or lipid support agents
  • Polymers used:
    • Ethylcellulose (e.g., Surelease®, Aquacoat® (IFF)
    • Eudragit® RS/RL (Evonik)
    • Polyvinyl acetate (e.g., Kollicoat® SR 30D (BASF))
    • Lipid-based systems (glyceryl behenate, carnauba wax)
  • Advantages:
    • Improved bioavailability for time-sensitive actives
    • Enhanced consumer compliance
    • Smoother pharmacokinetic profile

Formulation and Labeling Considerations

When designing coated nutraceutical products, formulators must consider a variety of technical, regulatory, and market-driven factors. Regulatory compliance is essential, with attention to GRAS (Generally Recognized as Safe) status in the U.S., EU additive codes, and certifications for natural or organic products. Labeling requirements also play a key role, often requiring the exclusion of synthetic colorants, palm-derived materials, or animal-based gelatin to meet consumer expectations for clean-label, vegan, or allergen-free claims.

From a production standpoint, the choice between pan coating and fluid bed coating systems, as well as aqueous versus solvent-based processes, can significantly influence formulation outcomes. Ensuring compatibility between the coating material and both the active ingredients and other excipients is critical to avoid issues during processing or storage. In addition, stability testing must account for the differences between coated and uncoated cores to ensure optimal shelf life and performance.

With increasing demand for plant-based, vegan, and non-GMO nutraceuticals, there is growing interest in using natural or nature-identical coating agents. These include shellac-free systems, starch-based films, and pullulan – each offering functional performance while aligning with clean-label trends.

Conclusion

Film coatings in nutraceuticals are no longer just about tablet appearance – they are essential tools for protecting sensitive actives, enhancing consumer experience, and enabling advanced delivery strategies such as enteric and controlled release. Whether the goal is to mask taste, extend release, or differentiate visually on the shelf, film coatings bridge science and branding in modern supplement development.

As the PharmaExcipients article on pharmaceutical film coatings states, the choice of a coating system must consider functionality, regulatory landscape, and consumer perception. For nutraceutical formulators, this translates into a delicate balance between performance and positioning – delivering tablets that are not only effective, but also appealing, safe, and aligned with evolving market expectations.