Aseptic Packaging: Ensuring Product Safety and Extended Shelf Life
Last updated: 28 January 2026
An aseptic packaging refers to the packaging of products under sterile, controlled conditions to prevent contamination. In this process, the content and packaging material are first sterilized separately and then brought together and sealed in a sterile environment. Through this process, germs are reliably kept away, so that accordingly pretreated (e.g. UHT- or sterile-filtered) foods, beverages or pharmaceuticals remain durable without refrigeration. In contrast to conventional cold storage (where the product must be actively cooled), aseptic filling takes place in a controlled, sterile environment. A pioneering form of aseptic filling is Blow-Fill-Seal (BFS) technology, in which container forming, filling and sealing are carried out fully automatically in a single, closed process step and without human intervention.
Packaging solutions
Different primary containers are used for aseptic packaging. Common examples are:
BFS containers: These single-dose containers (ampoules, bottles) made of plastic are formed, filled and then directly sealed in the so-called Blow-Fill-Seal process. This fully automated process minimizes human intervention and is particularly suitable for sterile liquids from a few milliliters up to 1000 ml. In addition, BFS containers offer the advantage of good recyclability, as they are typically made of pure monomaterials (e.g. PE or PP) and thus contribute to the sustainability strategy of many companies.
Infusion and injection bags: Flexible plastic bags are used for aseptic filling of larger volumes (such as infusion solutions). They are filled and sealed in closed systems, if necessary under an inert gas atmosphere to avoid oxidation.
Aseptic cartons: Multilayer carton composites (paper-aluminum-plastic) are used for liquid foods such as UHT milk, juices or soups. These packages have barriers that keep germs, light and oxygen out, so that the products are durable for months without refrigeration.
Sterile vials and prefilled syringes: Prefabricated glass or plastic ampoules as well as prefilled syringes are aseptically filled with medicinal solutions after sterilization. They are usually pre-sterilized and then sealed in a clean room so that the sterility of the filled drug is maintained.
Special containers: In special cases, e.g. multi-chamber bags, injection-molded plastic bottles or puncture bottles are used, which are aseptically filled (e.g. for cell culture media or emergency infusions).
Processes of aseptic packaging
The aseptic filling process typically consists of several steps, all of which must be validated:
Sterilization of product and material: First, the product (for example by high-temperature heating or sterile filtration) is freed from microorganisms. Separately, the containers and other packaging materials are sterilized (e.g. in steam chambers or by radiation). Note: In the BFS process, no separate sterilization of the primary container is necessary, since it is formed in situ from the molten polymer in a sterile environment.
Preparation: After sterilization, the product and container enter a clean room (usually class A, according to ISO 5). The staff enters this area only with special protective clothing through airlocks to avoid any contamination.
Aseptic filling: Within the clean room, the sterile product is filled under strictly controlled conditions into the sterile prepared containers. Modern systems operate fully automatically, partly in unattended operation (“lights out” mode), so that human intervention is largely eliminated.
Sealing: Immediately after filling, the containers are hermetically sealed (e.g. by welding or by applying a sterile cap). Thus, the interior remains permanently germ-free.
Testing and packaging: The sealed packages are checked for tightness and freedom from particles (e.g. vacuum leak tests, optical inspection). Only then does the secondary packaging (cartons, bundles) take place, also under cleaned conditions.
Use in the pharmaceutical industry
Aseptically packaged products also play an important role in the pharmaceutical industry. Sterile dosage forms such as injection and infusion solutions, eye drops, sprays or vaccines are filled. This process makes it possible to dispense with preservatives and keep the products stable even without refrigeration. Experts point out that aseptic filling is one of the most complex tasks in drug manufacturing.
Application in other industries
Packages that are aseptic are also frequently used in other industries. In the food and beverage industry, for example, it enables, after pasteurization or UHT treatment, UHT milk, juices, soups or soy drinks to be filled into germ-free packages. The carton or bottle composites have barrier layers (aluminum, plastic) that shield not only microorganisms but also light and oxygen. Likewise, cosmetic and chemical companies use aseptic processes, e.g. for sterile lotions, disinfectant solutions or laboratory reagents.
Technological requirements
Aseptic filling lines must meet strict technical conditions:
Clean room technology: The filling area must be designed as clean room class A (ISO 5). In the BFS process, the critical zone (Grade A) is locally protected, so that the surrounding background area, depending on the system design, in many cases only needs to be designed as Grade C (ISO 7). This leads to a significant reduction in operating and investment costs. The air is supplied through HEPA filters, and particle and germ counts are continuously monitored (in class A: no detectable microorganisms and strictly limited particle counts).
Closed systems: Work is often carried out in closed isolators or RABS (barrier systems). These hermetically separate the sterile zone from the outside air. Material or personnel passages into the clean room take place through airtight airlocks with disinfection cycles (e.g. H₂O₂ vapor) to prevent contamination.
Sterilization integration: Pre-sterilizers are integrated into the system. Thus, containers or components undergo disinfection processes before entering. Inlet lines are passed through sterile filter systems to ensure an aseptic connection. All sterilization steps must be validated.
Automation and monitoring: Sensors continuously record parameters such as temperature, pressure, humidity and particle count. Cameras check the filling levels and can detect defective or foreign particles in the containers. A central control room creates an electronic batch record in the event of irregularities and triggers an alarm.
Materials and components: All product-contacting components (hoses, valves, seals) must be suitable for clean room processes and sterilizable. Single-use systems (SUS) are often used to avoid cross-contamination.
Validation and documentation: Each machine, each cleaning and filling step is qualified and documented. Samples, validation protocols and batch documents ensure that the process at any time meets reproducibly sterile standards.
Regulatory requirements
Strict legal regulations apply to aseptically filled products. In the EU, GMP Annex 1 “Manufacture of Sterile Medicinal Products” provides comprehensive requirements. It defines clean room classes, equipment standards, risk analyses and hygiene measures. The American FDA has also issued detailed guidelines on aseptic processing. In addition, there are standards for packaging systems (e.g. ISO 11607 for sterile barrier systems) as well as requirements in the pharmacopoeias. Overall, all process steps must be validated, monitored and documented so that medicinal product quality and patient safety are ensured at all times.
Challenges and developments
Aseptic packaging is constantly facing new challenges. The complex technology and highest purity requirements make research and operation costly. At the same time, the demands for sustainability are increasing: manufacturers are developing aseptic cartons with very high fiber content (e.g. up to 90% paper) and without aluminum layers in order to improve recyclability.
Technical innovations such as electron beam (E-beam) sterilization, automated filling lines and AI-supported inspection systems increase efficiency and safety. New regulations (such as the revised EU-GMP Annex 1) also require extended contamination control strategies. Overall, the systems and processes are continuously developing to further increase the efficiency, safety and sustainability of aseptic packaging.