Designing containers that prevent a decrease in the concentration of Drug Adsorption – Zelas™CP, a low-adsorption container material that enhances product formulation flexibility.

In recent years, the beauty and healthcare sector has seen a growing trend of consumers choosing products based on their ingredients rather than brand image or recognition—a phenomenon known as "ingredient-based purchasing." Maintaining the quality of active ingredients has become a crucial factor influencing product value. However, often overlooked are packaging-related issues such as ingredient adsorption and degradation due to container materials. Addressing these challenges, which cannot be fully resolved through formulation design alone, from the container side is key to successful development. This article will discuss the mechanisms of active ingredient degradation, countermeasures, and introduce resin materials that are attracting attention as a new solution.

Do you have any of these problems?

Causes and countermeasures for the decrease in active ingredient concentration

There are mainly two approaches to addressing the decrease in active ingredient concentration.

•   Formulation innovations: Stabilization through the inclusion of antioxidants, optimization of surfactant amounts, and pH buffering.

• Improved container materials: A resin that suppresses component adsorption is used in the innermost layer.

The latter, in particular, namely reviewing the container material, is effective in increasing formulation flexibility (differentiation from competitors) and shortening the development process, as it improves stability without changing the formulation.

Features of Zelas™CP (container material)

To address these challenges, our company developed Zelas™CP, a next-generation resin that balances heat-sealability, adhesion to other materials, appearance, and hygiene while suppressing the adsorption of active ingredients.

As an example of an oily component, tocopherol acetate (vitamin E) was used as the active ingredient to evaluate its adsorption behavior. The results showed that Zelas™CP exhibited a higher active ingredient retention rate compared to PE.
Zelas™CPsuppresses adsorption by combining multiple resins with structures that make it difficult for active ingredients to penetrate.

Zelas™CP boasts a low specific gravity and low moisture permeability comparable to polyolefins (PE and PP). Compared to PET and PS (polystyrene), it is lighter and reduces the risk of product content deterioration and evaporation during storage, enabling both lighter containers and improved content stability.

Zelas™CP exhibits high fusion properties with polyolefins (PE and PP), enabling container design using multi-layer blow molding and multi-layer co-extrusion. By placing Zelas™CP as the wetted layer (innermost layer) and using existing polyolefins (PE or PP) for the outer layer to adjust mechanical strength and appearance, design flexibility is ensured, making it easy to introduce into existing lines and a cost-effective improvement method.

The film-grade XLCP201 (under development) exhibits excellent heat-sealing properties with other Zelas™CP materials, making it possible to develop various forms such as pouch packaging and laminated tubes, which were difficult to achieve with PET.

Blow-molded CP208 offers exceptionally high transparency, creating a glass-like appearance. It combines the functionality of transparent packaging with the ability to protect active ingredients.

Zelas™CP originally has a proven track record as a material for pharmaceutical packaging containers. We will bring the reliable technology of high hygiene and low drug adsorption cultivated in the medical field to the cosmetics field as well.

Examples of applications where Zelas™CP can be used

• Cosmetics and Personal Care
  Various containers, (refill) pouches, and tubes for lotions, emulsions, serums, face masks, sunscreens, hair styling products, shampoos and conditioners, body soaps, professional salon products, and doctor-developed cosmetics.
• Toiletries and household goods
  Bottles, refill pouches, and sachets for hand soap, body lotion, mouthwash, cleaning and disinfecting agents, detergents, fabric softeners, etc.
• Quasi-drugs, over-the-counter (OTC) medicines, pharmaceuticals
  Bottles, pouches, and laminated tubes for topical solutions, ointments/creams, eye drops, mouthwashes, oral care preparations, and quasi-drugs for skin care.
• Other functional liquids and industrial applications
  Containers for insect repellent products, functional fragrances, and industrial liquids where the stability of specific ingredients is crucial (bottles, multi-layer containers, tubes, primary packaging materials, etc.).

For those who are interested

If you're facing challenges such as "preventing the reduction of active ingredients," "finding a container that can pass stability tests without changing the formula," or "solving adsorption problems with existing PE containers," then please consider evaluating Zelas™CP.

We also provide detailed technical data, adsorption evaluation results, and support for multilayer container design.
Please feel free to contact us using the form below.

References

1) Director, Pharmaceutical Affairs Bureau, Ministry of Health, Labour and Welfare. "Regarding the Establishment of Standards and Test Methods for New Pharmaceuticals," Pharmaceutical Affairs Bureau Notification No. 568, May 1, 2001. PMDA (Pharmaceuticals and Medical Devices Agency) Public Document.https://www.pmda.go.jp/files/000156301.pdf

2) Japanese Patent Publication No. 10-85304, "Method for preventing and adsorption of fat-soluble vitamins into containers," Published Patent Application, April 7, 1998.