A new loading and unloading system for freeze drying vials in pharmaceutical production epitomizes transport and handling technology at its finest. The combination of magnetically propelled “movers” with two high-precision, ultra-fast Stäubli Stericlean robots is truly impressive.
How do you load a freeze drying system with large quantities of very small glass vials under the hygienic conditions that are mandatory in the pharmaceutical industry? The answer comes in the form of a new system with robot-assisted conveying and handling technology.
For the past 30 years, HOF Sonderanlagenbau GmbH in Hessen, Germany, has specialized in lyophilization, and is now the market leader in the technologically challenging field of refrigeration and medical technology, where it continues to set standards in terms of performance and degree of automation in freeze drying. One recent example is a robot-assisted loading and unloading system for vials, which HOF Sonderanlagenbau GmbH unveiled for the first time at Achema 2022.
Freeze drying is the preservation method of choice for many pharmaceuticals that are supplied in vials for transfer to syringes in hospitals and doctors’ offices. This requires that the small vials are filled with the active ingredient and dried partially sealed in a freeze dryer, where water and other solvents are removed, i.e. the ice changes directly from a solid to a vapor without passing through a liquid phase. This is precisely what the new SIRIUS system from HOF Sonderanlagenbau GmbH is designed to do.
Just one look at the system in operation reveals that the HOF design team has developed something fundamentally new. The vials arrive from the bottling line in large numbers, with their caps only loosely attached. Magnetic movers then gently yet rapidly funnel them in nests of five into an oval circuit positioned in front of the freeze dryer, where two compact Stäubli TX2-60 Stericlean six-axis robots with special grippers are waiting to pick up 50 vials at a time.
When 10 movers, each with five vials, have parked themselves at the loading station, the robots take turns lifting the 50 vials from the movers and placing them on the shelf of the freeze dryer. The system has been carefully configured to ensure that the vials do not touch each other. Unloading after freeze drying takes place in reverse order and is supported by a pusher mechanism.
The entire process is carried out in an aseptic area – in an isolator or a RABS (Restricted Access Barrier System). Therefore, glass contact must be prevented, and the robots must meet all aseptic requirements for working in a Class A cleanroom environment. In this regard, they are fully compliant because HOF opted for the Stericlean versions, which furthermore achieve a long service life despite being subjected to intensive cleaning processes.
The system achieves a loading and unloading rate of up to 400 two-millimeter (2R) vials per minute. Consequently, one loading/unloading cycle takes no longer than 14 seconds.
SIRIUS is capable of handling all common vial formats ranging from 2R to 100H. This is facilitated in part by the Stäubli robots’ CS9 controller, which stores the format-specific movement paths and points. In the case of SIRIUS, the CS9 is connected to a Siemens PLC over a PROFINET (Process Field Network).
With the SIRIUS system, the pharmaceutical manufacturer can load and unload its lyophilization units for vials fully automatically, quickly and flexibly. This enhances process reliability and ensures the highest standards of hygiene. The senior management at HOF also appreciated the support Stäubli provided during the development phase in the form of advice and suggestions for optimization based on simulations and feasibility studies.