Search

Gas plasma is considered the fourth state of matter after gases, solids and liquids. In nature, more than 99% of matter is in the gas plasma state, including the interior of stars as well as aurora and thunder. Gas plasma can be artificially generated by various types of discharge including arc, corona, DC (direct current), glow, high/low frequency, micro, pulse, and streamer. The practical application of gas plasma technology is very broad and includes energy production, medicine, dentistry, material processing, environmental science and agriculture. Of particular importance is the recent development of gas plasma technology for microbiological applications.

Methyl methacrylate polymer (PolyMMA) is widely used as the composite resin for the dental plate. During the preparation process of PolyMMA by the polymerization reaction, benzoylperoxide (BPO) and N,N’-dimethylp-toluidine(DMPT) are added as the initiator and the stimulator, respectively. These compounds exhibit toxicity as well as a residue potential, their use raises concerns regarding human safety. The degree of elution into serum or saliva was determined to evaluate risk to the user. Analysis was by HPLC combined with solid-phase extraction using a C-18 column. The eluted compounds were found to be in the order of 10 to 70 ppm.

Microbial testing performed in support of pharmaceutical and biopharmaceutical production falls into three main categories: detection (qualitative), enumeration (quantitative), and characterization/identification. Traditional microbiological methods listed in the compendia and discussed by using the conventional growth-based techniques, which are labor intensive and time consuming. In general, such tests require several days of incubation for microbial contamination (bioburden) to be detected, and therefore management seldom is able to take proactive corrective measures. In addition, microbial growth is limited by the growth medium used and incubation conditions, thus impacting testing sensitivity, accuracy, and reproducibility. For more than 20 years various technology platforms for Rapid Microbiological Methods (RMM) have been developed, and many have been readily adopted by the food industry and clinical microbiology laboratories. Their use would certainly offer drug companies faster test turnaround times to accommodate the aggressive deadlines for manufacturing processes and product release. Some rapid methods also offer the possibility for real-time microbial analyses, enabling management to respond to microbial contamination events in a more timely fashion, and can provide cost savings and higher efficiencies in quality control testing laboratories. Despite the many proved business and quality benefits and the fact that the FDA\'s initiative to promote the use of process analytical technology (PAT) includes rapid microbial methods, pharmaceutical and biopharmaceutical industries have been somewhat slow to embrace alternative microbial methodologies for several reasons. The major reason is that the bioburden count detected by incubation method and rapid assay has great divergence. Rapid methods is a dynamic field in applied microbiology and one that has gained increased attention nationally and internationally over time. This topic has been extensively addressed at conferences and in published documents around the world. More recently, the use of alternative methods for control of the microbiological quality of pharmaceutical products and materials used in pharmaceutical production has been addressed by the compendia in an attempt to facilitate implementation of these technologies by pharmaceutical companies. The author presents some of the rapid method technologies under evaluation or in use by pharmaceutical microbiologists and the current status of implementation of alternative microbial methods.