Fwd: Past, Present, and Future: How to Verify a Clean Manufacturing Process

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From: Derek from Peptide Price <derekpruski@substack.com>
Date: Mar 26, 2026 at 12:51 PM -0400
To: tjphuhs@gmail.com
Subject: Past, Present, and Future: How to Verify a Clean Manufacturing Process

> When you look at a certificate of analysis, you’re not looking at one thing.
> ͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­͏     ­
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> Past, Present, and Future: How to Verify a Clean Manufacturing Process
> Derek
> Mar 26
>
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> When you look at a certificate of analysis, you’re not looking at one thing. You’re looking at a snapshot across three different windows of time. Each test answers a completely different question — and once you understand that, a COA goes from a piece of paper with check marks on it to an actual quality story.
> The Past Test — USP 85 (Bacterial Endotoxins Test)
> In plain English: “Was the manufacturing process clean and controlled before it got here?”
> USP 85 is the Bacterial Endotoxins Test (BET). It checks for endotoxins — toxic remnants left behind by certain gram-negative bacteria during the manufacturing process. Here’s the key thing most people miss: the bacteria themselves don’t have to be alive or present anymore. Even dead bacterial cells leave behind lipopolysaccharides (LPS) that can trigger serious inflammatory responses in a research subject.
> A passing USP 85 result tells you the facility that made this compound maintained controlled, clean manufacturing conditions. It’s a look backward — at the production environment, not what’s in the vial right now.
> The Present Test — HPLC-MS (Purity & Identity)
> In plain English: “Is this exactly what it’s supposed to be, and how pure is it right now?”
> High-performance liquid chromatography-mass spectrometry (HPLC-MS) is the gold standard identity and purity test. It confirms the compound’s molecular weight, composition, and sequence, and quantifies exactly how much of the actual compound is present versus impurities or degradation products.
> This is the test that tells you what’s in the vial today. A compound can come from a clean facility (pass USP 85) and still be mislabeled, misdosed, or degraded. HPLC-MS catches all of that. It’s the most critical test on a COA, and it’s the one you should always look for first.
> The Future Test — USP 61 (Microbial Enumeration)
> In plain English: “Is anything in here that could grow or cause problems over time?”
> USP 61 tests for the presence and count of live microbial contamination — bacteria, yeast, and mold — that could proliferate over time. Where USP 85 looks at manufacturing byproducts, USP 61 looks at living organisms that could be introduced during filling, storage, or handling.
> This is the forward-looking test. A product can be clean at the time of manufacture and still pick up contamination later. USP 61 is the standard microbial quality test used broadly across non-sterile pharmaceutical products and is what most research vendors use.
> The Sterility Test — USP 71
> In plain English: “Can we confirm there are absolutely zero viable microorganisms present?”
> USP 71 is the sterility test — it goes a step further than USP 61 by attempting to confirm the complete absence of viable microorganisms. This is the standard applied to products intended for injectable research and is used for injectable research compounds, biologics, and sterile preparations.
> The methodology involves incubating samples in growth media over 14 days to detect even a single colony-forming unit. If something grows, the batch fails. It’s a more rigorous standard, which is exactly why it carries different regulatory implications — and why you don’t see it universally across research vendors.
> Quick Reference
>
> • > USP 85 — Past → Was manufacturing clean?
> • > HPLC-MS — Present → Is it correct and pure right now?
> • > USP 61 — Future → Will anything grow over time?
> • > USP 71 — Future+ → Confirmed sterility (injectable research standard)
>
> Why Some Companies Opt for USP 61 Instead of USP 71 — Something to Keep in Mind
> USP 61 and USP 71 are often treated as interchangeable in the research space — and from a pure microbiology standpoint, they’re measuring similar things. Both look for live microbial contamination. But there’s a reason some companies deliberately choose USP 61 over USP 71, and it has nothing to do with cutting corners.
> USP 71 is the sterility standard for injectable research. Performing USP 71 testing signals — or can be interpreted as signaling — that a product is intended for injectable research. In a space where everything is labeled research use only, not for human consumption, that distinction carries real legal weight. I’ve spoken directly with research companies whose legal teams have explicitly prohibited them from conducting USP 71 testing for exactly this reason — not because the test itself is problematic, but because it can be used to imply an injectable research classification that exposes the business to regulatory risk.
> It’s a fine line, and the research space is still very undefined. Every company is going to have a different risk tolerance and operate accordingly. Some will opt for USP 71 and accept that tradeoff. Others will stick with USP 61 on the advice of legal counsel. Neither position is inherently wrong — it’s a business decision made in a space where the rules aren’t fully written yet.
> What’s worth knowing: the cost difference between the two tests is essentially zero. So when you see USP 61 on a COA, it’s not a budget decision. It’s likely a legal one.
> Keep this in the back of your mind when evaluating COAs. The presence of any microbial testing is a positive signal — and the gap between a vendor that does microbial testing and one that doesn’t is far more meaningful than whether they chose 61 or 71.
> Next time you pull up a COA, run through the three windows mentally. USP 85 — was it made cleanly? HPLC-MS — is it what it says it is right now? USP 61 or 71 — is anything alive in there? When a vendor hits all three, that’s a genuinely comprehensive quality picture. Whether they chose 61 or 71 often comes down to how they approach the legal side of things — both signal that they care about sterility and bacterial growth. When a vendor is missing one of the three windows entirely, you now know exactly what question isn’t being answered.
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