Optimizing a viral test strategy

 

Viruses are found in almost every ecosystem on Earth and are the most numerous types of biological entity. As such, viruses pose a challenge to many aspects of biopharmaceutical manufacturing. These challenges not only relate to viruses per se or viruses that pose a particular problem to different cell lines or production processes, but also from the varied nature of viruses themselves – the genetic material (molecules of DNA or RNA that encode the structure of the proteins by which the virus acts); the nature of the protein coat (the capsid, which surrounds and protects the genetic material) and whether or not the virus possess an outside lipid envelope.1 The shapes of these virus particles range from simple helical and icosahedral forms to more complex structures. These geometrically sophisticated architectures are influencing factors where nanofiltration is used as a viral inactivation step. Given the risk presented from both pathogenic viruses in starting materials and from adventitious agents arising during bioprocessing, the testing strategy becomes an essential part of the viral contamination control strategy.

 

 

In a previous issue of American Pharmaceutical Review, a strategy was outlined for viral reduction and virus clearance within a facility.2 This companion article considers the testing component of the overall viral strategy.

 

Sandle, T. (2022) Optimizing a viral test strategy, American Pharmaceutical Review, 25 (4): 46-51

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Examination of the growth rates of environmental isolates compared with compendial strains

 

For some years there has been a regulatory drive for microbiology laboratories to use environmental isolates for media quality control and for the incorporation into method suitability studies. Where these organisms are included in testing regimes, do they take longer to grow? This paper assesses the growth rates of environmental isolates in comparison with compendial recommended cultures. The research presented here finds that environmental isolates do take slightly longer to grow compared with laboratory strains, yet this time difference was within the recommended incubation times of each test type. Therefore, microbiologists should generally expect slower growth but test methods may not need to be adapted to compensate.

 

To read this new paper by Tim Sandle, see: EJPPS

Reference:

1.      Sandle, T.(2022) Examination of the growth rates of environmental isolates compared with compendial strains, European Journal of Parenteral and Pharmaceutical Sciences, 27 (2):  https://doi.org/10.37521/ejpps.27201

 

 Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Tim Sandle's publications list, 2022 update

Here is an updated list of my published works:

Publications by Tim Sandle - 5th edition by Tim Sandle on Scribd

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Cleaning matters: The effective use of cleaning as part of contamination control

 

Cleaning together with disinfection is of great importance within pharmaceutical and healthcare products facilities in order to minimise contamination presence in cleanrooms. Contamination consists of debris, soiling and microorganisms. Conceptually, cleaning and disinfection are two distinct, although interlinked, processes. Cleaning is an important preparatory activity that is always required prior to disinfection, in order to remove any soil or residues that carry the potential to inhibit the effectiveness of the disinfection process to reach, make contact with, and kill microorganisms.

 

Cleaning is the process of removing residues and ‘soil’ (such as dirt, grease, protein residues and so on) from surfaces to the extent that they are visually clean. This involves defined methods of application and often the use of a detergent. Importantly, the act of cleaning is necessary prior to the application of a disinfectant for a surface needs to be properly cleaned before the application of a disinfectant in order for the disinfectant to work efficiently, as disinfectants can either be inactivated by organic residues or the soil can create a barrier which prevents the disinfectant from reaching all of the microbial cells. When applying a detergent (or disinfectant) to the target surface, the approaches are either without mechanical action (such as simply directly spraying) and with mechanical action (spray and wiping or soaking and wiping).

 

 

Whilst "cleaning" is not "disinfection" the cleaning process can remove or dilute microbial populations. Furthermore, many detergents have chemical additives that can 'disinfect'. However, a cleaning agent will not meet the criteria for disinfection required by the European and United States standards for disinfectant validation in terms of reducing a microbial population of a defined range by the required log reduction.

 

This paper looks at the importance of cleaning, application methods, and the role cleaning should play in validating the cleaning and disinfection process.

 

Sandle, T.(2022) Cleaning matters: The effective use of cleaning as part of contamination control, STAXS white paper, at: http://staxs-5651425.hs-sites.com/cleaning-matters?utm_content=212286549&utm_medium=social&utm_source=linkedin&hss_channel=lcp-2003328

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)