Aseptic processing microbial contamination

The major source of microbial contamination of controlled environments is personnel. Since the major threat of contamination of product being aseptically processed comes from the operating personnel, the control of microbial contamination associated with these personnel is one of the most important elements of the environmental control program. Personnel training should be conducted before the qualification and validation practice [13]. 

The manufacture of sterile products is universally acknowledged to be the most difficult of all pharmaceutical production activities to execute. When these products are manufactured using aseptic processing, poorly controlled processes can expose the patient to an unacceptable level of contamination. In rare instances contaminated products can lead to microbial infection resulting from products intended to hasten the patient s recovery. The production of sterile products requires fastidious design, operation, and maintenance of facilities and equipment. It also requires attention to detail in process development and validation to ensure success. This chapter will review the salient elements of sterile manufacturing necessary to provide acceptable levels of risk regarding sterility assurance. 

Ordinarily, present within the preparation area are localized areas of ISO 5 unidirectional airflow (Class 100) utilized to protect washed components prior to sterilization and/or depyrogenation. These areas are not aseptic and should not be subjected to the more rigorous microbial expectations of aseptic processing. They are designed to reduce/eliminate the potential for particle contamination of unwrapped washed materials. Operators accessing these protective zones wear gloves at all times when handling materials. 

Table 1 Most likely sources of microbial contamination in aseptic processing ...

Because of advanced computer control (auxostat mode) and an anaerobic culture, sterilization of the feed, aseptic techniques, and sparging of the broth are not required. Using standard equipment mills, waste paper would be shredded directly into the reactor. This avoids expensive pre-suspending of the paper in a separate tank, prevents microbial contamination of the feed stock, and circumvents difficult pumping of paper slurries. Once the acetic acid has been extracted, some of the broth could be recycled back to the reactor. If the product were mixed calcium/magnesium salts, the solution could be concentrated to form crystals and sold. While the process control is sophisticated, the overall system represents a low cost approach for the production of acetic acid mixed with small amounts of other acids. The obvious application is acetate salts for deicing of highways. 

For the production of monacolin K-containing MRP on an industrial scale especially, we have successfully developed a fermentation process by cultivating a low-citrinin, high-monacolin K-producing strain of M. purpureus on rice in an aseptic rotary vessel to minimize microbial contamination due to the slow growth of Monascus. In brief, steamed rice was inoculated with M. purpureus with an inoculum of 100 spores/kg raw rice. The inoculated rice was cultivated at 30 °C for 5 days until the steamed rice turned a deep red color. The colored rice was used as "seed Koji." The "seed Koji" was uniformly mixed with steamed rice at a ratio of 3% based... 

Aseptic Processing Area (APA) Controlled environment, consisting of several zones, in which the air supply, equipment and personnel are regulated to control microbial and particulate contamination to acceptable levels. 

Closed systems provide for complete separation between the environment in which personnel (uniformly accepted as the primary source of contamination in aseptic environments) are located from that in the materials are processed. Theoretically, if a sterile BPC could be processed in its entirety within closed systems, there would no possibility of microbial contamination. In marked contrast to the closed system is the open system , perhaps best defined by what it is not. Essentially, an open system lacks one or more of the features of a closed system, thus leaving it vulnerable to the potential ingress of contamination. One substantial issue associated with these definitions is establishing that a system remains closed over the length of the production campaign. 

To reduce risks of microbial contamination, aseptic processing is executed in a controlled environment, in which the air supply, facility, materials, equipment and personnel are regulated to control microbial and particulate contamination to acceptable levels [3]. Contact between product and environment should be minimised, sterile equipment should be used, and there should be two consecutive filtration processes through sterile 0.2 pm filters. The first filter will minimise the microbial challenge to the second filter, which should be just before the sterile final container. The shelf-life of the product is often restricted and it may be stored in the refrigerator to further reduce the risks of microbial growth. 

Normally, fermentation processes can be classified depending on the objective of study. For example, in terms of products fermentation is divided into 4 types, namely, microbial cell, microbial enzyme, microbial metabolite and transformation process. If considering due to its contaminating conditions, it will be classified into 3 types septic, semi-septic and aseptic fermentation. However, in general, the fermentation processed are classified into 3 types as follows. 

When proteinoids were heated in buffer at pH 6.2 or 6.8, loss of catalytic activity was observed. The extent of loss ranged from 95 to 11% (Table II). Those proteinoids that initially showed higher levels of activity relative to histidine were the most affected by the heat treatment. After heating, the level of activity was comparable to that of the equivalent amount of histidine, or to that of mineral acid hydrolysates of the polymer. Under similar conditions, a-chymotrypsin was 97% inactivated. The fact that the control tests on L-histidine or A -carbo-benzoxy-L-histidine showed no effect is consistent with the inference that inactivation is due to disruption of a macromolecular conformation. Copolymers prepared from only aspartic acid and histidine were also active on NPA and were inactivated by the heat treatment. The percentages of inactivation ranged from 62 to 19. Polymers prepared and processed under aseptic conditions were both catalytically active and subject to inactivation by heat. These experiments were performed as routine verification that the respective phenomena do not result from the presence, and subsequent denaturation, of contaminating microbial enzymes. 

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