Lyoprotect® Bag for Lyophilization

Lyoprotect® Bag for freeze-drying without contamination: for bulk and vials

You freeze-dry substances in an open container or in vials with a lyo-plug for the development of drug formulations? And in the process, you often have to deal with the unpleasant side effects of fly-out?

The Lyoprotect® Bag is the answer to this problem.

Contamination and fly-out with vials

Fly-out with vials in an open container



The Lyoprotect® Lyophilization Bag completely encloses your container, protecting it against any kind of contamination. Fly-out during freeze-drying remains safely in the bag, cleaning procedures or a cleaning validation of the freeze-drier are not necessary. The environment remains contamination-free, occupational exposure limits (OEL) are met.

Aseptic criteria can be met as well: For this purpose, the container or vials with plugs will be autoclaved in the sealed Lyoprotect® Bag, opened under the laminar flow, filled and closed again. Alternatively, you can autoclave all components individually in sterilization bags and then assemble them under the laminar flow. Both procedures ensure aseptic dry substances.

Lyoprotect® bag prevents contamination and fly-out

Working principle of the Lyoprotect® Bag

The upper side of the bag consists of a vapor-permeable membrane and the bottom side of a gas-tight film. The membrane is sufficiently porous, so that it doesn’t represent any resistance during sublimation; on the other hand, it is sufficiently impermeable, so that no germs, contaminants or particles will pass through the membrane.

Consequently, both the product inside the bag and the environment are reliably protected from contamination.


The drying process within the Lyoprotect® Bag

The freeze-drying process will take place as usual. Drying parameters determined with open containers can be used. If you have any questions regarding acceleration of the drying process or resolving the thermal resistance of the bottom film, our partner company ProJect Pharmaceutics GmbH in Martinsried (near Munich, Germany) will be happy to assist. ProJect Pharmaceutics develops drying cycles for major pharmaceutical customers, amongst others with the Lyoprotect® Bag – especially with regard to toxic and cytotoxic substances.


Examples of use and procedures

Lyoprotect® Bag with multiple-use stainless steel tray

The open stainless steel tray (often referred to as product tray) has the quality 1.4404 (ANSI 316L) and can be obtained in the following standard dimensions: 270 mm x 400 mm or 350 mm x 400 mm or round with a diameter of 200 mm. If required, other dimensions can be manufactured for optimized footprint utilization.

Lyoprotect® Bag with open tray and closing stick

Lyoprotect® Bag with single-use polypropylene tray

Individual dimensions and shapes of disposable polypropylene containers can be manufactured in a thermoforming process for optimized footprint utilization.

A good standard solution are PP trays used in the food industry. They are available in the dimensions of the Gastro Norm (DIN EN 631). Examples: GN 1 (530 x 325); GN 2/3 (354 x 325); GN ½ (265 x 325); GN 1/3 (176 x 325) or other GN dimensions.

Lyophilization in vials with the Lyoprotect® Bag

A frame or tray is used to accommodate the filled vials. These are preferably arranged in the middle of the frame or tray, and the lyo-plugs are in the drying position. Empty positions within the frame or tray should be filled with empty vials, so that all vials are secured.

Lyoprotect® Bag Tray Vials Open

The tray or frame containing the vials will then be placed in the lyophilization bag, which is already in place in the freeze-drier. For the frame, an auxiliary sheet will be used. It will be removed after positioning the frame. Then, the bag is closed and secured with the Closing Stick.

If aseptic criteria must be met, filling of vials, placement in the bag and closure of the bag can take place under a laminar flow. For the handling from the laminar flow to the freeze-drier another auxiliary sheet will be used (outside the bag), which is removed after the bag has been placed on the shelf in the freeze-drier.

When the drying process is finished, the vials can be securely closed with the lyo-plug. This is done within the freeze-drier by lowering the shelves. The flexible materials of the Lyoprotect® Bag easily follow the movements and mechanical loads when the plugs are pushed in.

Lyoprotect® Bag Tray Vials Closed

The complete process is also visualized in this animation:


If the video doesn’t play in your browser, click on this link to watch it on YouTube:

Please read more about contamination-free freeze-dyring in vials in this Case Study.



Closing the Lyoprotect® Bag

For secure closing we offer a Closing Stick, which we adjust to the individual bag size.

Closing Stick for Lyoprotect®Bag

The closing stick is reusable and available with our Lyoprotect® bags.


Contact us for questions or your unbinding quote!

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