Here's how it's typically done:
1. Sanitary Design and Materials
- Materials:
- Wahal High shear mixers used in sterile applications are constructed from materials that meet stringent sanitary requirements, primarily SS 316L stainless steel.
- Elastomers and seals are chosen for compatibility with sterilization processes (e.g., SIP) and the products being manufactured.
- Surface Finish:
- The Wahal mixer's internal surfaces undergo high-level polishing (e.g., electropolishing) to minimize crevices and facilitate cleaning.
- This smooth surface finish reduces the risk of microbial buildup.
- Clean-in-Place (CIP):
- Wahal High shear mixers are designed for CIP, allowing for automated cleaning without disassembly.
- This involves incorporating spray balls, optimized flow paths, and drainable designs.
- Sterilization-in-Place (SIP):
- For critical sterile processes, the mixers must be compatible with SIP, typically using steam sterilization.
- This requires materials and designs that can withstand high temperatures and pressures.
2. Aseptic Connections and Integration
- Aseptic Connections:
- The Wahal mixer's connections to the skid's piping and vessels utilize aseptic connectors (e.g., tri-clamp fittings) to maintain sterility.
- Integration:
- The mixer is integrated into the skid's process flow to ensure seamless material transfer and processing.
- This involves careful design of piping, valves, and instrumentation to minimize dead legs and maintain sterility.
- Seals:
- Mechanical seals that are used must be sanitary, and able to withstand the sterilization processes.
3. Process Control and Monitoring
- Instrumentation:
- Sensors and instrumentation are integrated into the skid to monitor critical process parameters, such as speed, temperature, and pressure.
- This data is used to control the mixing process and ensure consistency.
- Automation:
- The Wahal mixer's operation is often automated as part of the skid's control system.
- This allows for precise control of mixing parameters and reduces the risk of human error.
- Validation:
- The complete integrated system will need to be validated, to prove that the sterile process is reliable.
4. Considerations
- Containment:
- In some applications, particularly those involving potent compounds, the mixer may be integrated with containment systems to protect operators and the environment.
- Scale-up:
- When scaling up production, it's essential to select a high shear mixer that can maintain consistent performance at the desired production volume.
In essence, the integration of high shear mixers into sterile manufacturing skids involves a holistic approach that prioritizes sterility, cleanability, and precise process control.
