On this page
What belongs in the CTD introduction in section 2.2?
CTD section 2.2 briefly identifies the pharmaceutical, its pharmacological class, mechanism of action and proposed clinical use. It orients the reviewer to the application before the detailed summaries. Write it from the agreed product description and indication, and keep efficacy arguments and detailed evidence in the relevant summaries.
Before you begin
A CTD marketing-application introduction. An IND or a lifecycle submission needs its own applicable content decision; this page does not make every Module 2 document mandatory.
What you will prepare: A short, reconciled introduction with an agreed product identity and a clear statement of the proposed use.
Resolve the identity before drafting the paragraph
Start with the proposed labeling, controlled product description and regulatory submission plan. Ask the product owner to confirm the pharmacological class, mode of action and proposed clinical use. The M4 introduction is an orientation to the pharmaceutical; it is not a substitute for the analyses in the quality, nonclinical and clinical overviews.
Keep a working distinction between an established attribute and a proposed claim. “Proposed for treatment of…” describes the application objective. “Proven superior…” makes an evidentiary claim that needs a defined comparator and analysis. If the indication is still being negotiated internally, retain the unresolved wording in the working record rather than quietly selecting the broadest version.
M4 recommends that the introduction not exceed one page. Treat that as guidance about focus, not a technical rule that proves adequacy. The useful output is an intelligible introduction, not a page filled to a target length.
Use a compact writing sequence
An editorial sequence is: identify the pharmaceutical, orient the reader to its pharmacological role, explain the proposed use, and add only the context needed to understand this application. Use the same product name, active substance and indication vocabulary used elsewhere in the dossier.
Prepare a four-row working table: identity, pharmacological class, mechanism, proposed use. Beside each entry record the source section and responsible reviewer. Do not copy an exploratory mechanism from an early slide deck into a definitive statement if the current evidence supports only a hypothesis.
Review the introduction after the substantive summaries stabilize. A late change in population, route or presentation can make a previously accurate introductory sentence misleading. The short document should be easy to reconcile; it should not become a second, separately maintained source of product facts.
Worked example: a proposed population changes
Fictional editorial exercise: the first draft describes use in all adults. The final clinical overview supports a narrower population after prior therapy. The introduction still uses the original broad description.
Compare the population phrase with the current indication proposal. Replace it with the agreed scope and ask the clinical owner whether any mechanism or class language also needs qualification. Do not add a promise of agency approval. Record the discrepancy as resolved only after the responsible owner confirms the wording.
If the proposed population is unavailable, preparation can continue on verified identity information, but the intended-use sentence remains unresolved. A polished paragraph is not a reason to guess the application’s central claim.
A working outline for a one-page introduction
Use the following as an editorial planning sheet, not as a compulsory agency template. Its purpose is to decide what each sentence must establish before drafting.
| Sentence function | Information to collect | Reject or revise when |
|---|---|---|
| Identify the pharmaceutical | Current active-substance name, product description and relevant development identifier | Different dossier sections describe different substances or presentations |
| Explain pharmacological context | Agreed class and supported mechanism description | A proposed mechanism is stated as proven or a laboratory result becomes a clinical claim |
| State proposed use | Indication, intended population and relevant conditions of use | The wording exceeds the population or use proposed in the application |
| Add necessary orientation | A fact needed to understand this application, such as the relationship to an existing product | The paragraph becomes development history, a study summary or promotional positioning |
Draft in that order, then remove sentences that merely repeat the table of contents. Read the result without the rest of the dossier: a reviewer should know what the product is and what use is proposed. Next, compare it with the quality overall summary and clinical overview. Names and indication wording should agree, while each document keeps its own purpose.
A useful drafting scaffold is: “[Product identity] is a [supported class description] intended for [proposed use]. Its [established or proposed] mechanism involves [supported description].” These brackets are work instructions, not content to submit. If a field cannot be completed from a controlled source, obtain that decision; do not fill the space with marketing language.
Your preparation checklist
0/4 checkedUse this to track your review in this visit. Checks are not saved and do not establish regulatory compliance.
Frequently asked questions
How long should the CTD introduction be?
ICH M4 recommends that the introduction generally not exceed one page. That is guidance on keeping the orientation brief, not a guarantee of technical acceptance or a reason to omit essential product context. Move detailed development history, evidence and benefit-risk reasoning into the appropriate summaries.
Is section 2.2 the same as the nonclinical introduction in 2.6.1?
No. Section 2.2 introduces the pharmaceutical and proposed use to the overall CTD reader. Section 2.6.1 provides the nonclinical context, including the product properties and intended clinical regimen relevant to understanding the safety program. Reconcile shared facts without replacing one document with the other.
Can the introduction say that the product is safe and effective?
A broad promotional conclusion is a poor substitute for the introduction’s purpose. Describe the product and proposed use accurately. Put evidence-based efficacy, safety and benefit-risk interpretation in the relevant clinical summaries and overview, with its population, conditions and limitations visible.
When should the introduction be finalized?
As an editorial workflow, draft it early to expose unresolved product facts, then reconcile it after the quality and clinical summaries stabilize. A later indication, formulation or route change can invalidate a short sentence even when the rest of the introduction remains unchanged.
Sources and revisions
Requirements, source recommendations and editorial preparation advice have different roles. Review the scope and revision of the source you use.
Guidance
ICH M4: Organisation of the CTD ↗Step 4, June 15, 2016; Module 2 organization. FDA corresponding M4 guidance is final, October 2017. Format guidance, not a universal list of required studies.
Technical specification · placement only
FDA eCTD v4.0 comprehensive hierarchy ↗Version 2.2, February 2025. Section 2.2. A heading identifies placement, not mandatory applicability.