Environmental Analysis 43 BSE/TSE-free vegetable media


Because TSA contains animal ingredients that may possess the potential to transmit BSE/TSE, contact plate media have become available that contain no substances of animal origin at all. The growth promoting properties of one such solid vegetable contact medium was tested for various strains originating from culture collections (see Fig. 1). The results indicate culturability roughly comparable to that of TSA.


Material of non-animal origin, and thus free of BSE/TSE, is also used for media fill trials, which are conducted at regular intervals to simulate the actual filling process as closely as possible. In these trials, media is used instead of the pharmaceutical ingredients. Like animal-based peptone media, these vegetable media allow growth of a similarly broad range of microorganisms. In quantitative tests of 20 Gram positive and 8 Gram negative bacterial strains as well as 8 fungal strains, the growth-promoting properties of this vegetable peptone broth were found to be similar to those of Tryptic Soy Broth (TSB). 3


All-in-one swabs


For testing irregular surfaces, such as equipment recesses, nooks, crevices, tubing and filling needles, where contact plates are difficult to cope with, pre-moistened swabs may be used to validate cleaning and sanitation procedures and to verify that a required level of cleanliness has been reached.


For maximum recovery the swab is carefully removed from its tube and rubbed across a surface area using a twisted motion. Conventional swabs are then resuspended in a specified amount of rinse solution and agitated to transfer any microorganisms present on the swab head into the solution. The collection medium is then tested, usually by either direct plating or membrane filtration and incubation of filters on culture media.


A drawback of conventional swabs is that the recommended procedure involves a number of steps, each of which carries the potential for handling errors and thus adventitious contaminations. To undertake without having to open the tube several times, an all-in-one swab system has been developed which requires opening only once because it already carries with it a reservoir containing the culture broth. After returning the swab to the tube, the reservoir at the top is snapped and squeezed until the broth floods the swab head. After incubation the broth is monitored for turbidity, which would indicate contamination. This ICR swab is gamma-sterilised in its final packaging at a relatively high dose of 25-35 kGy. Despite this, both the moistened swab tip and the medium were shown to be non-inhibitory against the challenges of eight microbial species that are more commonly isolated from aseptic processing environments. 4


This swab is also


suited for use in isolators because it is triple-packaged, with the inner bag possessing a pre-punched hole to hang it up.


Figure 1: Recovery rates of microbial strains on a solid vegetable contact medium and TSA (test in duplicate) Instrumentation properties for reduced risks


Instruments used to actively sample air for microbes or particles draw a pre-determined volume of ambient air. Microbial air samplers direct the air stream at an agar plate or strip for collection. It is important that the air flow is not disrupted by the instrument’s operation, placement or removal, as contaminants then find it easier to attach to its housing. The MAS-100® and RCS High Flow Touch air samplers (Merck Millipore) are specifically designed with rounded edges to minimise air flow disruption. To minimise disruption in isolators and other confined areas and to save space, manufacturers have developed variants of their instruments. Their air ducting is directed from the sampling points outside the controlled area where all electronic and moving parts remain. The internal pumps of the instruments enable easy decontamination of the sample heads and aspiration tubes.


Additionally, particle monitoring of ambient air is regularly


3Hedderich, R., Klees, A., Eiermann, K., Greulich, Y. and Müller, R. (2009): Growth promoting properties of a vegetable peptone broth (VPB) in comparison to tryptic soy broth. Poster at PDA Annual Global Conference on Pharmaceutical Microbiology. 4Sandle, T. (2011): A study of a new type of swab for the environmental monitoring of isolators and cleanrooms (the heipha ICR-Swab). European Journal of Parenteral and Pharmaceutical Sciences, Vol. 16, No.2, pp42-48.


conducted to determine the air quality in controlled environments. In many pharmaceutical production facilities, the particle counters are pre-installed. However, if the need arises to modify the particle counting system at a later date, this can prove disruptive. Many pharmaceutical companies thus opt for the flexibility of portable particle counters. For example, Merck Millipore’s APC SmartTouch can be programmed from a touchscreen and is able to display a visual representation of a cleanroom’s sampling locations, thus reducing the likelihood of human errors in sampling. Because it is equipped with two high-capacity batteries, it can sample continuously without the need for downtime during recharging. With all the pros and cons to consider, it is usually a strategic decision whether to choose pre-installed or portable particle counters.


MAS-100 is a registered trademark of Merck KGaA, Darmstadt, Germany.


Precision Under Extreme Conditions


Hamilton (Switzerland) SaltLine syringes stand out because of their exceptional resistance. Conceived for use in connection with the tried and tested Hamilton Microlab 600 Diluter/Dispenser, they allow precise dosing even under extreme environmental conditions. Thus, they meet the toughest day-to-day requirements of challenging industries such as the mining and chemical industries.


Aggressive media or saturated salt solutions, as they are used in the mining and chemical industries, make very high demands on the performance of analytical syringes. Hamilton SaltLine syringes were specifically designed for resisting the toughest working conditions. Even in the most difficult applications, they guarantee the precise dosing of highly concentrated buffer solutions for long periods.


The plunger sealings of SaltLine syringes are made from chemically inert and mechanically resistant ultra-high molecular weight polyethylene (UHMWPE). When handling 5% sodium chloride solutions, they last twice as long as conventional PTFE sealings. Not only is their sealing force constantly high, but they also resist numerous aggressive media and organic solvents as well as the abrasion caused by deposited salt crystals or other particles.


The plunger rods of the SaltLine syringes are made of fibre-reinforced, high-performance polyamide. Since no metal is present, they resist corrosion and also eliminate the distortion of measuring results caused by migration of metal ions.


The wetted syringe surface is neutral. All fluid paths are fully inert and made of glass, UHMWPE, or fluorinated polymers. SaltLine syringes are ultra-precise; with a syringe partial volume of one percent, accuracy and precision lie between one and three percent at most (depending on the total volume used by the syringe). With an ejection of 100 percent, the syringes operate accurately down to 0.2 percent.


SaltLine syringes were conceived to be used exclusively with the Microlab 600 Diluter/Dispenser, the tried and tested fluid control device also from Hamilton. Thanks to the advanced dispensing technology based on the displacement principle, the Microlab 600 guarantees 99 percent accuracy—regardless of viscosity, temperature, and steam pressure. The high-resolution syringe pump even allows the programming of small sample volumes. More advantages of the device are higher precision and throughput plus lower buffer consumption compared to manual solutions. Since the Microlab 600 has a universal valve, users can also switch very quickly from one application to another.


Reader Reply Card No. 119 www.envirotech-online.com IET November / December 2012


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