Chemistry, Manufacturing and Controls Community

Hello AAPS Friends,

I am posting this as a thread to facilitate discussion regarding modern industrial blend uniformity testing practices. From what I have been able to gather, current guidance has been established via the International Society for Pharmaceutical Engineering (ISPE) as of 2014, after the FDA announced withdrawal of its Powder Blends and Finished Dosage Units draft guidance. However, it also seems that there are industry partners who potentially still employ the Product Quality Research Institute blend uniformity recommendation document (2002) guidance. Overall, I am hoping this post can help serve as a catalyst for communication/collaboration on current practices employed for blend uniformity testing, most especially clarification on testing practices and acceptance criteria followed.

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Bo Tokarski Ph.D.
Sr. Analytical Chemist, R&D
Hims & Hers
New Albany OH
[email protected]

Disclaimer: Opinions expressed are solely my own and do not express the views or opinions of my employer.
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Thanks for starting a thread on the BU topic.  It's just great to have the BU thoughts of ISPE hidden behind a membership requirement.

I have done BU/CU on many OSD products and have a few opinions and would really like to collaborate with an industry partner to generate and publish product data to support an extremely simple method to potentially justify eliminating BU testing in certain cases.  BU is subject to so much sampling error that it is really an exercise in developing a sample method that allows you to meet whatever criteria you are comparing against.   Of course, if you have a real BU problem, you may not be successful.

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Dwayne Campbell Ph.D.
President
DCC Pharma Consulting LLC
Cary NC
[email protected]

Disclaimer: Opinions expressed are solely my own and do not express the views or opinions of my employer.
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Original Message:
Sent: 7/13/2026 4:08:00 PM
From: Dwayne Campbell
Subject: RE: Blend Uniformity Testing

Thanks for starting a thread on the BU topic.  It's just great to have the BU thoughts of ISPE hidden behind a membership requirement.

I have done BU/CU on many OSD products and have a few opinions and would really like to collaborate with an industry partner to generate and publish product data to support an extremely simple method to potentially justify eliminating BU testing in certain cases.  BU is subject to so much sampling error that it is really an exercise in developing a sample method that allows you to meet whatever criteria you are comparing against.   Of course, if you have a real BU problem, you may not be successful.

------------------------------
Dwayne Campbell Ph.D.
President
DCC Pharma Consulting LLC
Cary NC
[email protected]

Disclaimer: Opinions expressed are solely my own and do not express the views or opinions of my employer.
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Thanks for your response, Nagarjuna, and thanks for your patience in my response. I do certainly think a webinar or virtual discussion would be beneficial to have regarding BU testing for industry partners to engage and discuss the topic. If this opportunity arises, I will help pursue it and hopefully set something up for the community to participate in.

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Bo Tokarski Ph.D.
Sr. Analytical Chemist, R&D
Hims & Hers
New Albany OH
[email protected]

Disclaimer: Opinions expressed are solely my own and do not express the views or opinions of my employer.
------------------------------

Original Message:
Sent: 07-14-2026 08:18
From: NAGARJUNA MAMIDIPALLI
Subject: Blend Uniformity Testing

Dear AAPS Group Members,

Thank you for initiating this important discussion on BU testing. I appreciate the opportunity to engage with experts and stakeholders on this topic and learn from the collective experience within the community.

I would greatly appreciate it if we could consider organizing a webinar or virtual discussion with subject matter experts and key stakeholders to further explore the challenges, best practices, and emerging approaches related to BU testing.

Thank you again for starting this conversation, and I look forward to the continued discussion.

Best regards,
Nagarjuna Mamidipalli.

Sent from my iPhone

Original Message:
Sent: 7/13/2026 4:08:00 PM
From: Dwayne Campbell
Subject: RE: Blend Uniformity Testing

Thanks for starting a thread on the BU topic.  It's just great to have the BU thoughts of ISPE hidden behind a membership requirement.

I have done BU/CU on many OSD products and have a few opinions and would really like to collaborate with an industry partner to generate and publish product data to support an extremely simple method to potentially justify eliminating BU testing in certain cases.  BU is subject to so much sampling error that it is really an exercise in developing a sample method that allows you to meet whatever criteria you are comparing against.   Of course, if you have a real BU problem, you may not be successful.

------------------------------
Dwayne Campbell Ph.D.
President
DCC Pharma Consulting LLC
Cary NC
[email protected]

Disclaimer: Opinions expressed are solely my own and do not express the views or opinions of my employer.
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Thank you Dwayne for replying, and thanks for your patience in my response. I definitely think a white paper on blend uniformity would be most beneficial. We are currently investigating best practices for blend uniformity internally. I would definitely like to stay in touch regarding potential collaboration on the potential of bypassing BU in favor of CU as justification for representation of uniformity in the batch across the entire process.

------------------------------
Bo Tokarski Ph.D.
Sr. Analytical Chemist, R&D
Hims & Hers
New Albany OH
[email protected]

Disclaimer: Opinions expressed are solely my own and do not express the views or opinions of my employer.
------------------------------

Original Message:
Sent: 07-13-2026 16:08
From: Dwayne Campbell
Subject: Blend Uniformity Testing

Thanks for starting a thread on the BU topic.  It's just great to have the BU thoughts of ISPE hidden behind a membership requirement.

I have done BU/CU on many OSD products and have a few opinions and would really like to collaborate with an industry partner to generate and publish product data to support an extremely simple method to potentially justify eliminating BU testing in certain cases.  BU is subject to so much sampling error that it is really an exercise in developing a sample method that allows you to meet whatever criteria you are comparing against.   Of course, if you have a real BU problem, you may not be successful.

------------------------------
Dwayne Campbell Ph.D.
President
DCC Pharma Consulting LLC
Cary NC
[email protected]

Disclaimer: Opinions expressed are solely my own and do not express the views or opinions of my employer.
------------------------------

Thanks to everyone for the valuable discussion on the BU topic. For most OSD and pellet products, BU sampling variability often leads to ASTM acceptance criteria failures, primarily due to higher standard deviation values. However, the finished product content uniformity generally complies with USP <905> requirements, with AV values well within the acceptance limit (typically AV < 5).

As an industry, we may need to engage with regulatory agencies to explore a more practical approach for solid dosage forms. Even when blend uniformity exhibits relatively high variability, the subsequent tablet compression or capsule filling process often results in finished products that consistently meet USP <905> content uniformity requirements.

Input and recommendations from industry experts on this matter would be greatly appreciated.

Regards

Selvaraja

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Selvaraja Elumalai
Director Quality Control
Granules USA, INC.
Chantilly VA
[email protected]

Disclaimer: Opinions expressed are solely my own and do not express the views or opinions of my employer.
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