The processing of lyophilized vials or any other parenteral product which takes the form of a sterile powder presents challenges that are not present in other sterile filling procedures.
Many parenteral products and bulk drug ingredients are not stable in liquid or frozen form. Some naturally take a powder form at room temperature, while others require lyophilization in order to be safely stored, transported, and handled prior to administration or use.
In any case, sterile powder can be filled into vials and other containers using vacuum technology and cleanrooms via a similar process to aseptic filling of other parenteral products. However, handling sterile powder brings with it a unique set of challenges which need to be planned for before a CMO begins the process of aseptic filling.
While lyophilized compounds are often more stable than those in liquid form, powders are messier and sometimes harder to handle than liquids. Because they lack the surface cohesion of a liquid, keeping a powder together in a sterile environment requires precise control of air flow, static electricity, and other variables.
Controlling these unique variables calls for technology and processes that may not be necessary for other aseptic filling procedures. Not every manufacturer is prepared for the risks and difficulties that come with handling sterile powder filling, and some may find it more expedient and economical to contract out the work to CMOs that are already equipped for sterile powder filling.
Sterile powder filling can be a messy, difficult process — but it has its rewards.
According to Cherish Robinson, a Product Specialist at Gore PharmBIO Products, “One of the biggest problems in lyophilization is the mess it can create.” That problem isn’t limited strictly to lyophilized vials. It is also true of any powdered substance, especially one that needs to be handled in an aseptic environment.
Most everyone has experienced the frustration of trying to pour flower, powdered sugar, or cinnamon into a small container in the kitchen. Now, magnify that frustration by the added hurdles imposed by the needs of aseptic filling. That’s a snapshot of the challenges facing CMOs and other manufacturers who deal with sterile powders.
Anything that is messy is also at greater risk for contamination, not to mention that once powders become dispersed they may not reconstitute as well or experience reduced efficacy across the entire batch.
Fortunately, CMOs aren’t filling lyophilized vials or other parenteral products in the kitchen. They have highly specialized equipment and clean rooms that help to alleviate the challenges that come with handling sterile powder, ensuring that vials and other containers are filled to the correct amount, and that both powder and containers remain sterile throughout the process.
Advances in technology and current best practices can help CMOs handle sterile powder safely and efficiently.
Much of the handling of sterile powder relies on vacuum/pressure machines that can operate inside a cleanroom environment. Trays of vials can be introduced and filled via automated processes, assuming that the sterile powder in question has an adequate flow characteristic. Flow characteristics can also influence the speed and reproducibility of fills.
For powders whose flow characteristics do not enable easy automation, other solutions may be required in order to ensure proper handling. Regardless of the sterile powder being handled, R&D trials and regular validation are vital in order to ensure that the powder is handled properly in an aseptic environment and that the final product retains its efficacy throughout.
Fortunately, there are numerous solutions available that follow all cGMP guidelines for sterile powder filling.
Technology helps put sterile powder filling within reach for manufacturers of all sizes.
As with any other type of aseptic filling, different solutions are available to meet different needs. Some CMOs specialize in lyophilized vials or handling one kind of sterile powder, while others perform fills for numerous different types of product, into vials and containers of varying sizes. The equipment used by each varies depending on their needs, their workflow, and the size of their batches.
Small batches of sterile powder require different machinery and different processes than handling larger batches, just as the container size and flow characteristics of the powder can affect production, speeding production up or slowing it down, or introducing the necessity of additional steps to ensure even disbursement of powder.
Ultimately, the tool that’s right for each manufacturer will depend on the product that they’re trying to produce, the characteristics of the powder being handled, the size of the batches they’re processing, and the unique needs of their workflow.