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Microbiological Considerations of Biotechnology Products

Microbiological considerations. First, we need to consider sterility. Now, because most therapeutic proteins are administered parenterally. Therefore, they must be sterile. And it must be free from viral decontaminations as well. Because as many recombinant DNA products are prepared from microorganisms. And therefore, there’s a potential for viral contamination. Pyrogen free, that is to remove the pyrogens that induce fever. Sterility of biotech products. Now, unfortunately proteins are sensitive to heat. Therefore, you can not use heat sterilization. You cannot use steam sterilization. And you can not use gas sterilization, either. In addition, proteins are sensitive to radiation. Therefore, ionizing radiation should be carry out if at all with high level of caution.
And that leaves the filtration as the alternative to remove the bacteria; to remove the particulate matter. But they have a tendency to return on the filter paper, so you’re going to lose some material by way of filtration.
So the best way is to prepare the product under ascetic conditions. That is under sterile conditions. So let’s talk about asceptic conditions. Aseptic conditions regard to the environment. For example, the room. Aseptic conditions with regard to the equipment the equipment that you used. So we can use dry heat to sterilize the equipment, for example. And aseptic with regard to the operator, to the personnel. So the sterile coveralls with sterile hats, mask, goggles, and even foot covers. Aseptic environment. The environment is free of bacteria by the use of ultraviolet light, by UV light to kill the microbes. And the environment is free of particles by the use of Laminar Flow Hoods to filter the air.
And the air quality class must be 100 or better. Air quality control. We use high-efficiency particulate air filter that is the so-called HEPA filter, High Efficiency Particularly Air. And that filters 99.97% to remove the point three micron or larger particles. And again air quality must be class 100. What does it mean by air quality, air class 100? That is the number of particles per cubic foot, must contained no more than 100 particles greater than 0.5 micron. So that’s the specification for air class 100. And we must use air class 100 for the preparation of biologics. Laminar flow hood. Basically, there are two types of laminar flow hood. The laminar flow claim benches and the biological safety cabinets.
And the air is flow out from the hood to suspend and remove the contaminants.
And the constant flow, that is maintained at the laminar flow hood, also prevent the room air from entering the operation room. That is to prevent the draft. And the laminar flow hood should be run for 24 hours a day, or if it is turn off, it should be turned back on at least 30 minutes before used.
So here that are the two types of laminar flow hood. Depending on the direction of the airflow and this is the vertical and this is the horizontal. And the average speed of the airflow is about two meter per minutes, plus minus ten percent. And you are allowed to recirculate the air. And here is the biological safety cabinet which is used for the preparation biohazard material such as biologic. And that is to prevent harming the personnel or the environment. And again, it’s used for cytotoxic drugs. And we normally are usually pre-filtered air to get rid of and 90% of the particles greater than 5 micron. That is just to make the air filtration more efficient.
And here you see up to 30% of the air could be recirculated.

The selection of a sterilization strategy for a drug product that requires aseptic manufacturing is generally determined by the stability of the drug substance. For stable products, terminal sterilization, including heat sterilization or exposure to radiation or chemicals such as ethylene oxide or vaporous hydrogen peroxide, is the preferred strategy. However, most biologic drugs are unstable when exposed to heat, radiation, or chemicals and generally require aseptic manufacturing using sterile filtration. Successful sterile filtration requires a drug product formulation with an appropriate viscosity and compatibility with the contact surfaces and shear stresses involved in pumping the fluid. Single-use technology is widely used in sterile fill/finish operations today, reducing the turnover time and cross-contamination risk.

Most biologic drugs are unstable when exposed to heat, radiation, or chemicals and generally require aseptic manufacturing. Several elements are to be considered for aseptic processing, the environment, the equipment, the operator, and the air quality. Specifications for each of these elements are illustrated, followed by the application of laminar flow hood and biological safety cabinet. Viral decontamination of biologics is a quality control of paramount importance since many biologics are derived from microbiological sources involving virus or bacteria.

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Pharmacotherapy: Understanding Biotechnology Products

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