The Analytical Target Profile: Deciding What a Measurement Must Do Before Choosing How to Do It

The usual order of events is: pick a method, run it, get a number, then ask whether the number is good enough. ICH Q14 proposes the reverse, and gives the reversal a name.

Quick answer

What is an analytical target profile? ICH Q14, the international guideline on analytical procedure development adopted on 1 November 2023, defines it as consisting of a description of the intended purpose of the analytical procedure, appropriate details on the product attributes to be measured, and relevant performance characteristics with associated performance criteria. In plainer terms: what are you measuring, why, and how good does the answer have to be.

The guideline is explicit about what this document is for: the ATP drives the choice of analytical technology. It is written before the method exists, because its job is to decide which method to build.

The order the guideline recommends

Step 3 contains the liberating part. Several techniques will usually clear the bar. Once the bar is written down, the choice between them becomes a question of cost, availability and convenience rather than an anxious guess about which is “better”.

Why writing it down changes the outcome

An unstated requirement cannot be failed. It can only be disappointed after the fact, which is why so many measurement problems present as surprises rather than as predictions.

Consider the two questions a research buyer most often asks of a measurement:

• “Is this lot the same as the last one?” The requirement here is resolution of a difference, not absolute correctness. A method with a known systematic bias answers this perfectly well, provided the bias is constant — the reasoning set out in accuracy and recovery.
• “How much peptide is in this vial?” This one needs absolute correctness, which means a reference, a traceability chain and an uncertainty — a far heavier requirement, described in metrological traceability.

Those are different measurements. Running the second when you only needed the first is wasted effort; running the first when you needed the second is a wrong answer. Only a written requirement distinguishes them in advance.

What belongs in one

Following the guideline's own structure, a usable ATP for research work needs four things:

1. Intended purpose. The decision the number will be used to make. “To compare lots from one supplier” is a purpose. “To know the concentration” is not — it does not say how well.
2. The attribute. Concentration, purity, identity, degradation — stated precisely enough that the unit is obvious.
3. The performance characteristics that matter. Not all five. For a lot comparison, precision dominates and accuracy barely signifies; for an absolute content claim, accuracy and range carry the weight.
4. The criteria. Numbers. “Able to resolve a 10% difference” is a criterion. “Accurate” is not.

It is a living document, not a filing exercise

ICH Q14 states that the ATP is maintained over the lifecycle and can be used as a basis for lifecycle management, to ensure that the existing, revised or new analytical procedure remains fit for the intended purpose. It also notes the ATP facilitates ongoing monitoring and continual improvement.

That is the part with practical teeth. When a method is later changed — a new column, a new instrument, a different principle entirely — the question “is the new one acceptable?” has an answer only if the requirement survived. Without it, every change becomes a fresh argument from first principles.

Formal submission is optional

Worth stating plainly, because the formality of the term puts people off: the guideline says formal documentation and submission of an ATP is optional, though it can facilitate regulatory communication irrespective of the chosen development approach.

So this is not a regulatory obligation being recommended to a research laboratory. It is a one-page habit borrowed from a context where its value has been worked out carefully, and it costs nothing to adopt.

A worked example, in four lines

Four lines, written before anything is measured, and every subsequent question — which method, how many replicates, is this difference real — now has somewhere to be answered from.

Key takeaways

• ICH Q14 defines an ATP as the intended purpose, the attributes to be measured, and the relevant performance characteristics with their criteria.
• It is written before the technology is chosen, because the guideline states the ATP drives the choice of technology.
• Multiple techniques may meet the criteria; the written requirement turns the choice into a practical one.
• Different questions need different measurements — comparing lots needs precision, stating absolute content needs accuracy and traceability.
• Validating characteristics the decision does not rest on is effort that buys nothing.
• The ATP is maintained across the lifecycle and is what makes later method changes assessable.
• Formal documentation and submission are optional; the value is in having written the requirement down at all.

Frequently asked questions

Is this only relevant to regulated manufacturing?

The guideline is written for that context, but the idea does not depend on it. Any measurement made to support a decision has a requirement, whether or not anyone states it. Stating it is free.

How detailed does it need to be?

Detailed enough that someone else could tell whether a proposed method would satisfy it. If two people could read it and disagree about whether a method qualifies, it needs numbers.

What if I do not know what criteria to set?

Start from the decision. If you would act differently on a 10% difference but not a 3% one, your resolution requirement is somewhere between. Measuring your own repeatability, as described in precision, tells you whether that requirement is achievable.

Does the ATP replace validation?

No. It sets the targets that validation then demonstrates have been met. ICH Q14 says the ATP serves as a foundation to derive the procedure attributes and performance criteria for validation under ICH Q2.

Can one profile cover several measurements?

Yes — the guideline states an ATP includes measurement requirements for one or more quality attributes. In practice one profile per decision is easier to keep honest than one covering everything.

Sources

• International Council for Harmonisation. ICH Harmonised Guideline Q14: Analytical Procedure Development. Final version adopted 1 November 2023. ICH guideline
• International Council for Harmonisation. ICH Harmonised Guideline Q2(R2): Validation of Analytical Procedures. Final version adopted 1 November 2023. ICH guideline

Guideline text is quoted from the adopted ICH documents.

This article describes analytical methodology only. It contains no usage instructions, no dosing information and no protocols of any kind.

For laboratory and in-vitro research use only. Not for human or veterinary use.