Südpack develops mono-PE sterile barrier system

Südpack Medica has developed a tubular mono-PE sterile barrier solution for demanding life science applications. Designed as an alternative to conventional PE/PA/PE laminates, the structure combines resistance to mechanical stress with reduced migration risks and compatibility with existing polyethylene recycling streams. The development objective was to match the performance of a PE/PA/PE structure without using polyamide or other components regarded as critical in the formulation.

Requirements for life science packaging are becoming more stringent. In addition to product safety, process stability and regulatory compliance, the circular economy and resource efficiency are receiving greater attention, although the pharmaceutical industry is not currently subject to all requirements of the Packaging and Packaging Waste Regulation (PPWR). Against this background, Südpack Medica designed the solution for use as outer packaging for process bags in sensitive cell culture and bioprocessing applications.

The film protects primary packaging against mechanical stress and damage during transport, storage and handling. Unlike conventional PE/PA/PE laminates, it is made entirely from polyethylene. This removes the need for polyamide, adhesives and other potentially migratable substances present in conventional coextruded structures. The resulting tubular bags are produced at several facilities, including the company's new ISO Class 7 clean rooms in Coulmer.

Requirements for sterile barrier systems

PE/PA/PE coextruded films have long been used as a standard solution for applications exposed to high mechanical loads. Polyethylene provides sealing and processing properties, while polyamide typically delivers the required stability and mechanical strength.

In the life science sector, potential interactions between packaging materials and sensitive biotechnological processes are closely examined. Even small quantities of migrating substances can be a serious concern in certain applications. This has created a need to improve packaging systems and minimise potential contamination sources.

Mechanical properties and migration risk

The tubular bag solution, optimised to meet cytotoxicity criteria, uses a barrier system made entirely from polyethylene. According to Südpack Medica, it matches conventional PE/PA/PE structures in mechanical performance and barrier properties. The company achieved this through extensive raw material screening, targeted material selection and optimisation of the coextrusion process.

Internal tests indicated high puncture resistance, strong resistance to flex cracking, and reliable processing and sealing properties. The film also maintains high transparency and optical quality.

For this application, Südpack Medica states that the sterile barrier system is currently the only solution on the market that does not contain migratable substances of concern associated with conventional PE/PA/PE coextruded films, including caprolactam, antioxidants, slip agents and adhesives. The material concept is intended for sensitive process applications and takes account of the sector's regulatory expectations.

Compatibility with PE recycling streams

Environmental considerations were also included in the development process. The mono-PE structure is compatible with established PE recycling streams and achieved a calculated recyclability rate of 100% in an internal assessment conducted with CHIRA software.

A screening life cycle assessment carried out by Südpack Medica indicated a reduction of more than 50% in carbon dioxide equivalent emissions compared with an equivalent PE/PA/PE structure. The result relates to the reference systems evaluated in the project and the assumptions used in the analysis.

The new sterile barrier system provides life science product manufacturers with an additional option for adapting existing packaging concepts to future regulatory and technical requirements. According to the development results reported by the company, the mono-material structure combines mechanical performance, regulatory compliance and recyclability.