Antibiotic Assays

A brief history of the antibiotic assay

The quantitative use of zones of agar made inhibitory to the growth of one microorganisms by diffusing substances produced by another organism was in use at least as early as 1885 (Analytical Microbiology, Kavanagh, 1963). The first official assays of penicillin were carried out in 1943. Publication of the theoretical aspects involved was published by Cooper and Woodman in 1946 in Pathological Bacteriology. The antibiotic assay used by pharmaceutical companies is primarily the agar plate diffusion assay. Some products that are a mixture of polymers may have a specific monograph stating that they must be assayed by a turbidimetric method. Such an example is Gramicidin. Continue reading

Writing Technical Reports

What is technical writing?

Technical writing is a style of writing used when preparing protocols, reports, investigations and other laboratory documentation.

What are some examples of technical documents?

In general, any regulated manufacturing site will use the following technical documents: validation documents, reports, Standard (Operating) Procedures, SOP’s and Work/Operator Instructions (OI’s), standard forms and overriding policies and a Site Quality Manual all within the framework of a Quality Management System (QMS), Continue reading

The Importance of Trending

What is Trending?

Trending, when used in a pharmaceutical microbiology laboratory, is the examination of long term data in order to examine if a controlled process is moving away from the state of control. Trending can also be used to determine the stability of a product’s efficacy by examining the results of testing over time. Stability trends are important to support expiry dates and storage conditions. Continue reading

Viable Environmental Monitoring

This was repurposed into a LinkedIn article as part of my Developing My Writing While Helping Others series.

What Is Viable Environmental Monitoring (VEM)?

Viable Environmental Monitoring (VEM) is the monitoring of factors within a production environment that may have an impact on the quality of goods produced within the environment. Typically this is any physical object than could support or introduce microbial contamination to a manufacturing environment: air, gases, surfaces (both on introduced objects and within the production room), liquids and people.  This discussion does not extend to Environmental Monitoring such as particle counting, temperature, pressure differentials, etc. Continue reading

What Makes An Objectionable Organism?

What is a specified organism?

A specified organism is one that according to the pharmacopeia, cannot be present in a sample (usually 10g). These microbes are specified either as they may be an indicator organism (a microbe where its presence may indicate a pathogenic microbe could be present) or they may actually pose product safety concerns (whether by reducing the efficacy or posing a risk to the end user). Continue reading

The Need for Documentation

“If It Was not Documented, It Was Not Done”

Reviewed and updated July 2020.

At one time there were three monkeys locked in a room. This room also contained a banana, suspended by a cord from the ceiling in the centre of the room. Whenever one of the monkeys grabbed the banana, all the monkeys were subjected to an icy cold shower. After several repetitions of this shower, no monkey in the room would touch the banana. Continue reading

Do SVP glass containers need depyrogenation

The Question posed on LinkedIn.

“We have all been working with the rationale that glass containers need to be depyrogenated. Depyrogenation meaning a measurable three log reduction of an initial concentration of Endotoxin.
We are now hearing about the impact of excess temperatures on the inner ‘skin’ of a vial and how some ‘hydration’ is lost when blasted with high temperatures and then we hear that after product filling, there could potentially be a ‘re-hydration’ of this ‘skin’. And finally all this dehydration and re-hydration potentially causing glass lamellae formation. (I am not a glass technologist, I’m groping around the dark here, feel free to correct any misconceptions!)
With all this concern about particulates, does it make sense to scale down glass vial heat treatments in SVP to sterilization temperatures rather than depyrogenation temperatures?
A vial which has been washed with a final rinse in hot WFI is not expected to have any significant level of endotoxin in it. Considering the volume adminstered, doesn’t it make sense to move to concentrating on sterilization rather than depyrogenation of an unrealistically large quantity of endotoxin load?”

My advice:

Yes. You must depyrogenate your containers where the product is being injected into the customer and regardless of rinsing or dry heat, you have to show you can remove pyrogens from your containers.

It would be UNWISE to use a sterilization protocol in an attempt to dehydrogenate your glassware if that if what you are suggesting. Pyrogens from when G- bacteria are destroyed. You need to physically remove them or “char them to death” for want of a better term. Using a sterilization to remove pyrogens will ultimately lead to dead customers and your company being severely affected.

You could scale back your temperatures when using a DHO as there is a range of temperatures allowed. Lower temperature equals longer exposure time. If your company is happy with the increased time it takes to make batches, then you could validate your new process and take it from there. If it is an amendment to your current process, then if it is a big enough one, you’d need to alter your product registration.

Regarding temperature effects on your vials. I’d examine where you heard the information and determine if they are a reputable source, determine what other companies are doing (and if the regulatory bodies have said that that’s an acceptable standard practice) and either enlist the services of an expert or conduct your own experiments.

Dehydrated Culture Media used in “Media Fill”

The Question posed on LinkedIn.

“Dehydrated Culture Media used in “Media Fill”. Does the powder specification need to be sterile (irradiated) or it can be sterilized by filtration (0.22µm) just after browth preparation in tank?”

My advice:

Your starting dehydrated media should meet your existing limits for raw materials with regards to microbial load.

If your standard procedure is to formulate your product in an ancillary room and sterile filter it on the way to the filling heads, then I would include this in your sterile media fill trials as it simulates your normal batch process.

A batch simulation with no interventions should demonstrate your filtration sterilises your “product”. Once that’s done, you can then incorporate interventions into your sterile media fill trials.