Process filters bioprocessing

Having seen the number of papers devoted to bioprocess analyses utilizing vibrational spectroscopy, it cannot be considered an experimental tool any longer. Manufacturers are responding to pressure to make their instruments smaller, faster, explosion-proof, lighter, less expensive, and, in many cases, wireless. Processes may be followed in-line, at-line, or near-line by a variety of instruments, ranging from inexpensive filter-based to robust FT instruments. Raman, IR, and NIR are no longer just subjects of feasibility studies they are ready to be used in full-scale production. 

C. Aubrun, J. Harmand, O. Gamier, and J.P. Steyer. Fault detection filter design for an anaerobic digestion process. Bioprocess Engineering, 22(5) 413-420, 2000. 

In bioprocessing, gas-phase pressure measurements are utilized for evaluation of the partial pressures of various gaseous components, to monitor the performance of outlet gas filters, and to control sterilization procedures. Since they are compatible with the aseptic requirements of biotechnological processes, membrane-type pressure sensors are most commonly used. 

Utility systems such as water for injection (WFl). clean steam, clean-in-placc (CIP) solutions and sterile process air must be similarly proven. Also the building system itself has to be validated. Many bioprocess operations which contain potentially hazardous materials are operated in closely-controlled negative pressure enclosures with filtration of exhaust ventilating air. Sterile and particularly parenteral products arc processed in clean rooms which are maintained at positive pressure with filtered incoming air. Validation of building control systems and of personnel changing facilities and systems of work are necessary to meet CMP requirements. Manuals for formal test procedures are required to validate these activities. 

Sintered glasses are commercially used as filters, carrier materials in bioprocessing, biomedical processes and also for thermal insulation, sound proofing and fire protection [166,177,466]. Porous glasses are used in separation processes, as supports for immobilised enzymes, as carriers for solid phase synthesis, for the immobilisation of biologically active materials and in membrane technology or for studying matter in confined spaces [263,264]. 

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