Question: Bracketed Stability studies…What are they and can they be used in compounding for stability studies? (Part II)

Answer:
Last week, we presented information about a very simple bracketed stability study that involved only two variables (strength and batch number). This week, we will present a table for a bracketed stability study that is somewhat more complex, which includes a third variable (in this example, package size).

Three Strengths: (50 mg, 75 mg, and 100 mg)
Three Package Sizes: (15 mL, 100 mL, and 150 mL)
Three Batches of Each Strength: (B)

“T� = Tested; “–� = Not Tested

The rationale for bracketing can include the following:

1. Interpolation between extremes is logical.
2. There is no need for the stability to be the same.
3. Savings (e.g., personnel, time, testing).

The issues against bracketing include the following:

1. Some preparations/products and their packaging may be dropped.
2. There is a potential for additions outside of the “bracket.�

Concerning “bracketing,� what is justified and what is not? Below is a brief summary:

• Strengths of identical or closely related formulations can be bracketed without further justification.
• Relative amounts of drug substances and excipient changes in a formulation can be bracketed with justification.

Continued next week

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

Pharmacists may wish to download and send to your state board of pharmacy for consideration.

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

Did you know that the new USP <797> BUD standards not allowing extended stability will effectively eliminate the usefulness of ALL published and nonpublished stability studies for BUDS in:

Trissel’s Handbook of Injectable Drugs
King Guide to Parenteral Admixtures
CompoundingToday.com
International Journal of Pharmaceutical Compounding
American Journal of Health-System Pharmacists
Annals of Pharmacotherapy
Pharmaceutical science journals containing stability studies:
     Journal of Pharmaceutical Sciences
     AAPS Pharmaceutical Sciences
     International Journal of Pharmaceutics
     Many others
Pharmaceutical compounding supply companies and pharmaceutical companies (PHARMA) that have funded and conducted hundreds of stability studies utilizing their drug substances and vehicles.

Did You Know ...

...that regarding Common Sense (CS), E. Hubbard (The Note Book, 1927) said that “Logic is one thing and CS is another?

CS is…

…the ability to detect values.
...the knack of seeing things as they are, and doing things as they ought to be done. (E.C. Stowe)
...an uncommon degree in what the world calls wisdom. (S.T. Coleridge)

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Looking Back

The crowd you see,
Around the store,
Are Burma-Shavers,
Buying more!
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