Question: Bracketed and Matrixed Stability studies…what are they and can they be used in compounding for stability studies? (Part III—Final)

Answer:
Let’s briefly look at “Matrixing�; it is primarily used in large scale stability studies but could be considered for use in compounding stability studies.

Matrixing involves a statistical design of a stability schedule such that a selected subset of the total number of possible samples are tested for all factor combinations at a specified time point. At a subsequent time point, another subset of samples for all factor combinations is tested. The design assumes that the stability of each subset of samples tested represent the stability of all samples at a given time point.

One is testing the same drug product, but matrixing may cover different batches, strengths, container sizes, and container-closure systems. One simple example involving 3 batches and 8 time points is as follows. All batches at the beginning and end will be tested, but only 2 of 3 batches in between.

The rationale for matrixing involves the following:

• Long-term trends are approximately linear
• Design can be such that the effect of each factor may be determined
• Can evaluate comparative stability of each presentation of product
• Can revert to full testing
• Saves resources

There are some limitations involved with matrixing that may also need to be considered, if interested. Generally, bracketing would be more beneficial in compounding stability studies unless involved in numerous batches, strengths, package sizes, and container-closure systems.

Next week, we will look at the latest EPA regulations affecting pharmacy.

Loyd V. Allen, Jr., PhD, RPh
Editor-in-Chief
International Journal of Pharmaceutical Compounding
Remington: The Science and Practice of Pharmacy Twenty-second edition

REMINDER: For those State Boards of Pharmacy that are not adopting the USP chapters and are preparing their own or using their own modifications of the chapters, easily-modifiable alternative versions of Chapters <795>, <797>, and <800> have been prepared and are available as a free download for use by state boards of pharmacy to modify for their individual states at the following website.

      CompoundingToday.com

News

“Clinical Need� Requirement Upheld
A U.S. District Court judge in Washington, D.C. issued a decision that upheld the FDA’s interpretation of clinical need regarding the bulk substances that may be used by outsourcing facilities in drug compounding. The FDA had previously announced that vasopressin is not a “bulk drug substance for which there is a clinical need� because there is already a product on the market that is FDA-approved to meet patients’ medical needs. The agency, therefore, decided not to place the bulk drug substance vasopressin on a list of bulk drug substances that can be used in compounding by outsourcing facilities (the “503B Bulks List�). The FDA’s oversight of compounding continues because compounded drugs, while important to patients who need them, pose ongoing and serious risks if they are not manufactured properly.

(NOTE: I believe the issue here is that vasopressin is available in only 1 strength and 3 vial sizes, and the request was to allow for different presentations of the drug. In preparing some admixtures, numerous vials may be used, increasing the potential for contamination. Also, without the API, what happens in case of a drug shortage?)
https://www.fda.gov/news-events/press-announcements/fda-statement-court-ruling-related-compounded-bulk-drug-substances-and-agencys-ongoing-efforts

Kroger Partners with Myriad Genetics to Offer GeneSight Genetic Tests and Genetic Counseling
A new pilot program is underway by Kroger that offers GeneSight by Myriad Genetics as a benefit. GeneSight is a laboratory-developed pharmacogenomic test used to treat psychiatric disorders, such as depression. As part of the agreement with Myriad Genetics, pharmacists at more than 2,300 Kroger stores will offer counseling about GeneSight to eligible employees and coordinate the testing with referring healthcare providers, according to a news release.

Last year, Albertsons Companies and Genomind, a personalized medicine platform, launched Genecept Assay (now known as Professional PGx)—a genetic test designed to help doctors make informed treatment decisions for their mental health patients—as well as pharmacy-based genetic counseling.
https://www.darkdaily.com/kroger-prescription-plans-partners-with-myriad-genetics-to-offer-genesight-genetic-tests-and-genetic-counseling-in-kroger-pharmacies/

Did You Know ...

…that someone has said, “I understand, and that’s what makes it simple!�?

Tip of the Week

How often do we have a task that seems formidable, and we tend to put if off? However, taking the first step to

• determine the scope of the task,
• search for information to help us out,
• organize it into smaller “chunks,â€�
• work on each “chunk,â€� and then
• pull it all together to make it easier.

We then look back at it and think, “That wasn’t as bad as I thought it was going to be,� and we have the satisfaction of accomplishing something.

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Looking Back

Guys whose eyes,
Are in their backs,
Get halos crossing,
Railroad tracks!
     Burma-Shave