1. What is High-Barrier Packaging, and What Does It Matter for Pet Supplements?
Pet supplements cover probiotics for pets, and glucosamine/chondroitin for joint health. But many pet supplements are sensitive to the following:
- Oxygen —It can oxidize fats and fat-soluble vitamins (A, D, E, K)
- Moisture—It can prematurely activate bacteria in probiotics, cause clumping, and encourage mold development.
- Light—It can degrade light-sensitive nutrients such as riboflavin and certain antioxidants
- Temperature changes—They increase the chemical reactions ratio that degrade potency
Is your product safe in packaging made with one layer of polyethylene or polypropylene? Materials with low barrier properties lack the protection needed to retain potency in pet supplements. You need high-barrier packaging structures, and it can be helpful in protecting your product from oxidation and preserving its potency.
3. Common High-Barrier Materials
High-barrier packaging is defined less by the material itself, and more by the combination of materials used for oxygen, moisture and light transmission control. Different material technologies have varying levels of protection, cost, processability, and sustainability.
The key to selecting the right technology is to consider not only its theoretical performance but also how it performs in the real world of storage and transport.
Aluminum Foil Laminates
Aluminum foil laminates continue to be the best high-barrier packaging. These usually consist of a laminated structure of PET combined with aluminum foil and a sealant layer (PE or PP), and essentially offer a zero oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) and a complete light barrier. These are suitable for highly oxygen-sensitive pet supplements, such as probiotics, omega oils and multivitamins, where even low levels of exposure can cause spoilage. But this protection is not without its drawbacks. Foil laminates are not recyclable in the conventional recycling stream because they are multi-faceted and non-transparent, which also makes them unappealing for use in retail packaging.
Metallized Films (VMPET, VMCPP, VMBOPP)
Metallized films are thin layers of aluminum applied to a plastic film to enhance barrier properties over films. Although not as impermeable as foil, they offer a balance for moderately sensitive products, such as tablets and capsules. Being lighter, cheaper, and more environmentally friendly, they are suitable for mass applications. Yet they have less mechanical stability. Creasing, folding or mishandling during transport can easily damage the metallized layer and lead to higher permeability. Therefore, they should not be used as a replacement for foil in high-risk products.
EVOH Multi-Layer Films
Ethylene Vinyl Alcohol (EVOH) is well known for its outstanding oxygen barrier performance, especially in dry environments. It is usually co-extruded as part of multi-layer structures, such as polyethene/ethylene vinyl alcohol/polyethene (PE/EVOH/PE) or polypropylene (PP) systems, where it is protected from moisture by the outer layers. A major benefit of EVOH is its clarity, enabling visibility of the product, which is a critical consideration for some markets. But EVOH is moisture sensitive.
During storage, exposure to high humidity can reduce its oxygen barrier properties, so the product’s structure is essential. With effective structural design, EVOH-based technologies, such as next-generation multi-layer packaging, provide a good balance of transparency, performance and cost.
Oxide-Coated Films (SiOx and AlOx)
Oxide-coated films, such as silicon oxide (SiOx) and aluminum oxide (AlOx) layers, are a relatively new class of barrier films. These films are coated with oxides via sophisticated deposition techniques to form a transparent barrier that enhances barrier properties to oxygen and moisture without compromising transparency.
They are gaining popularity among brands looking for a sustainable and high-end packaging solution, since they can be more recyclable than traditional foil laminates. But they offer moderate, not extreme, barrier properties and are sensitive to processing conditions and mechanical abuse. Scratches and abrasions can diminish performance, so quality control is critical.
4. Material Comparison of High Barrier Packaging
| Material | OTR | WVTR | Light Shield | Recyclable | Transparency |
| Aluminum Foil Laminate | ~0.001 | ~0.001 | 100% | No | Opaque |
| Metallized Film (VMPET) | 1–5 | 0.5–3 | ~95–99% | Partial | Opaque |
| EVOH Multi-layer | 0.1–0.5* | Varies | None | Difficult | Clear |
| SiOx/AlOx Coated PET | 0.5–2 | 1–3 | None | Potentially | Clear |
| Standard PE/PP | >100 | >10 | ~0% | Yes | Clear |
EVOH OTR decreases at relative humidity above 75%. OTR and WVTR values in cc/m²/day and g/m²/day, respectively.
5. Packaging Types and Format-Specific Considerations
1. Flexible pouches (Stand-Up, Flat, Spouted)
Flexible pouches are multi-layer laminates that offer an economical package format for powder, chew, and granule applications. Packaging seal durability is crucial to package performance. A premium high-barrier film will function ineffectively if seal allows ingress. Heat-seal strength and consistency must be validated throughout production.
2. Bottles with induction seal and condensation.
HDPE and PET bottles are widely used packaging formats for medicines. These resins do not provide good barrier performance. Barrier performance for the bottle format relies on the combined package container resin, induction foil seal, liner, cap, and desiccant packet. Every element needs to be qualified in order to meet the overall barrier requirement.
3. Blister packs
Cold-form aluminum (CFA) blisters afford the highest barrier available in blister packaging. Oxygen transmission rate (OTR) and water vapor transmission rate are close to zero. Less expensive thermoform blisters made from PVC, PVDC or PCTFE/OPA films can also be used and provide variable standards of protection. Cold-form aluminum is preferred for moisture-sensitive probiotics and enzyme products.
4. Sachets and stick packs
Single dose sachets and stick packs utilize similar laminate construction as pouches. Aluminum foil laminates are commonly used. This format decreases cumulative oxygen exposure as each individual dose is sealed from oxygen until the package is opened.
6. Selection Criteria for Choosing a Suitable Material
Use these four factors to narrow your selection:
| Factor | Questions to Ask | Impact on Selection |
| Product Sensitivity | Is the active ingredient oxygen-sensitive? Moisture-sensitive? Light-sensitive? | Higher sensitivity → foil laminate or cold-form blister |
| Shelf Life Target | 12 months, 24 months, or 36 months? What are the conditions of storage? | Longer shelf life → lower OTR/WVTR tolerance required |
| Format & Fill Line | What equipment is already in use or planned? | Equipment compatibility may constrain material options |
| Objectives for Sustainability | Do reduced plastic or recyclable claims need to be made? | Consider oxide-coated or mono-material structures |
| Budget | What is the per-unit cost target? | Foil laminates cost more than metallized films; oxide coatings are premium |
7. Issues with Validation and Regulation
It’s not enough to decide on a material that matches your needs in theory. The completed packaging system needs to be validated.
- Real-time stability studies are needed for regulatory declarations for most markets.
- Seal integrity testing—vacuum decay, dye ingress, or helium leak testing, depending on the package format.
- Migration testing is required in Europe and gaining acceptance in other markets to ensure undesirable substances do not migrate into your product
If you plan to sell your product in the US, the FDA mandates that your packaging must preserve the identity, strength, and quality. Additional substantiation may be required for packages that make certain health claims about the product.
8. Some mistakes to avoid:
- Choosing your package because it looks good instead of asking the supplier for OTR/WVTR data
- Not taking headspace oxygen into account.
- Need nitrogen flushing or an oxygen scavenger in addition to a barrier material.
- Expecting metallized film to perform like aluminum foil. It won’t.
- Skipping seal area integrity testing. More packages fail at the seals than through the film.
- Assuming you don’t need to re-validate when you change material suppliers, even if they’re the “same” spec.
Conclusion
Use of high barrier packaging is not a “nice to have” in pet supplements, it’s mandatory. The optimal solution will vary based on Product sensitivity, desired shelf life, package format and budget and sustainability initiatives
If you have an extremely sensitive product, aluminum will likely be your best option. Otherwise, high performing multi-layer structures offered by Srlon Group such as EVOH-based packages can be great alternatives.
The important part is not just picking a material, but specifying an end-to-end packaging system that you can test and prove works for your product.
FAQs
Q: What is the minimum barrier requirement for probiotic supplements for pets?
Probiotics require the highest barrier of all common supplement categories. Aluminum foil laminate or cold-formed aluminum blister packaging is needed. Some formulations require oxygen scavengers included in the package to maintain CFU counts throughout shelf life.
Q: Can metallized film replace aluminum foil?
No, for most products. Metallized films have OTRs 100–1000x greater than solid foil laminates. They are suitable for some products with lower oxygen sensitivity. Probiotics, fish oil, or any products making a shelf-life claim of 24+ months require foil laminate or cold-form blister for reliability.
Q: How does headspace oxygen impact packaging selection?
Oxygen already in the package at seal will break down sensitive ingredients even if the barrier prevents additional oxygen ingress. For products that are sensitive to oxygen, the barrier material must be used in conjunction with either nitrogen flushing or oxygen-scavenging sachets or films. Barrier materials can stop oxygen from entering the package; nitrogen flush or scavengers are used to deal with existing oxygen in the headspace.
Q: Can sustainable/recyclable packaging have a high barrier?
Foil laminates cannot be recycled through normal programs, as they are multi-material. Some options can provide sustainability without affecting the barrier: (1) mono-material PE or PP laminates with new high-barrier coatings, (2) oxide coated films (SiOx/AlOx) that are more recyclable. (3) chemical disposal techniques. None of these options currently matches the barrier performance of foil, but technology is advancing. Sustainability considerations should be weighed against shelf-life and barrier requirements for each individual product.
Q: How often should I repeat packaging validation?
Repeat full stability testing when the product formula changes, the packaging supplier or site of manufacture changes, the packaging specification changes (including minor changes such as film gauge), or the fill line equipment is changed significantly. Additionally, periodic re-testing is recommended.
