The Anatomy of the CTD/eCTD Registration Dossier and the Logic of Interconnections Across the Five Modules in EAEU Pharmaceutical Law
An experienced regulatory affairs specialist reads a registration dossier as a dependency map between documents. A thousand PDF files explain nothing on their own; what matters are the connections across sections. A single figure in a stability report within Module 3 can alter the shelf life stated on the packaging in Module 1. An unexplained adverse event in a clinical study report in Module 5 can result in a refusal of marketing authorization, even if Module 3 is compiled impeccably.
Regulatory teams that compile a dossier as five separate folders for five departments of the company routinely receive queries from expert bodies at the intersections between modules. The Common Technical Document (CTD) format was built by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) specifically to remove these disconnects. The electronic version of the format, designated eCTD (electronic CTD), adds XML-based file markup to the module structure. In Eurasian Economic Union (EAEU) law, the logic of the CTD is established by Decision of the Council of the Eurasian Economic Commission No. 78 of 3 November 2016, «On the Rules for Registration and Examination of Medicinal Products for Human Use» (hereinafter — Decision No. 78). The structure is set out in detail in Annex No. 1 to this Decision.
Why Five Modules Replaced National Archives
Before the CTD format appeared in the early 2000s, each national agency, the US FDA, EU regulators, Japan’s PMDA, imposed its own structural requirements on registration materials. Applicants reassembled the same scientific data under different tables of contents, translated it repeatedly, and lost time resolving formal discrepancies unrelated to the quality or safety of the product.
ICH proposed a pyramid model. The broad base (Modules 3, 4, and 5) contains primary data: study protocols, analytical procedures, and study reports. The middle tier (Module 2) turns this data into expert summaries. The apex (Module 1) remains a national or Union-level layer holding administrative documents, the Summary of Product Characteristics (SmPC), the patient information leaflet, and pharmacovigilance data.
The EAEU did not go through the gradual paper-to-electronic transition typical of the FDA and EMA. The registration rules approved by Decision No. 78 were built on CTD logic from the start. This let the Union adopt the established international structure immediately. Module 1 in the EAEU does not match EU or FDA templates, and applicants have to account for it separately.
Module 1 as the National Interface of the Dossier
Module 1 remains the only component of the dossier that is not subject to international harmonization. Annex No. 1 to Decision No. 78 sets out its structure in sections 1.0 through 1.11, and this numbering differs noticeably from what specialists familiar with EU formats might expect.
Section 1.0 is reserved for the cover letter. The table of contents for Modules 1-5 sits in a separate Section 1.1, though by analogy with other jurisdictions specialists sometimes look for it right at the start of the module. The application form itself is located in subsection 1.2.1, within the broader Section 1.2, which brings together all general documentation: proof of fee payment, the WHO Certificate of a Pharmaceutical Product, and a translation of the assessment report from the country of manufacture.
Documentation on Good Manufacturing Practice (GMP) inspections is collected in Section 1.6. Information on the specialists who prepared the quality, non-clinical, and clinical summaries is filed in Section 1.7. Section 1.8 in the EAEU is reserved for requirements specific to particular application types: a list of Good Clinical Practice (GCP) inspections (approved by a separate EEC Council Decision No. 79), comparability summaries for generics and biosimilars, and justification of patent status.
| Module 1 Section | Content | Language Regime |
|---|---|---|
| 1.0 | Cover letter | Russian |
| 1.2.1 | Application for registration (Annex No. 2 form) | Russian |
| 1.3 | SmPC, patient information leaflet, packaging mock-ups | Russian |
| 1.6.3 | Manufacturing site GMP inspection report | English permitted |
| 1.7 | Information on quality, non-clinical, and clinical experts | Russian |
| 1.8.2.2 | List of GCP inspections conducted for the product | Russian |
| 1.10.1 | Pharmacovigilance System Master File (PSMF) of the marketing authorization holder | English, summary in Russian |
| 1.10.3 | Risk Management Plan (RMP) | English, summary in Russian |
The language regime applies section by section, not to the whole module. Annex No. 1 explicitly allows the GMP inspection report (Section 1.6.3) to be submitted in English without translation, and the pharmacovigilance master file and risk management plan (Sections 1.10.1 and 1.10.3) are also accepted in English, provided the summary is translated into Russian. The pharmacovigilance master file itself is not required with every submission: the rule calls for it only when the marketing authorization holder registers a product on the Union market for the first time. For that holder’s subsequent applications, a brief characteristic of the pharmacovigilance system is filed instead of the full master file: confirmation that a qualified person is in place, the country where that person works, contact details, a declaration of commitment to pharmacovigilance rules, and a reference to where the master file itself is located. A specialist who translates these documents in full by default spends the client’s budget without any regulatory need to do so.
Section 1.9 stands apart: documents assessing the product’s environmental risk and, where applicable, a declaration on the presence of genetically modified organisms. This section is easy to overlook because it is not directly tied to quality or efficacy, but the expert body requests it whenever the document is missing from the dossier entirely.
Section 1.4 requires a list of countries where the product has been submitted for registration, registered, refused registration, or had its marketing suspended. Each country entry needs the number and date of the corresponding decision, and the marketing authorization holder certifies the whole list. Section 1.5 brings together quality documents that confirm the authority and obligations of the master file holder. The holder of the active pharmaceutical ingredient master file commits in writing to notify the manufacturer and the competent authority of any changes before they are made, and separately agrees to disclose the closed part of the master file at the competent authority’s request. For substances of animal origin, a certificate of compliance with the Pharmacopoeia of the Union or the European Pharmacopoeia on transmissible spongiform encephalopathy is added.
For products derived from blood plasma, a plasma master file certificate is added here too, and Section 1.11 closes the list with a copy of trademark registration documents, where one exists. Section 1.5 is easy to confuse with the substantive part of Section 3.2.S. Section 3.2.S describes the substance itself; Section 1.5 covers only the rights and obligations of the holder of someone else’s master file toward the manufacturer of the finished product.
Module 2 as the Assessor’s Entry Point into the Dossier
For an assessor, Module 2 is the first point of entry into the dossier and shapes the overall impression of the quality of the development programme. Annex No. 1 to Decision No. 78 assigns seven sections to Module 2: table of contents for Modules 2-5 (2.1), CTD introduction (2.2), Quality Overall Summary (2.3), Non-clinical Overview (2.4), Clinical Overview (2.5), Non-clinical Written and Tabulated Summaries (2.6), and Clinical Summary (2.7).
Module 2 explains the regulatory significance of the data in Modules 3-5. Simply duplicating that data without analysis does not fulfil the purpose of the section.
The Quality Overall Summary (2.3) must point to problematic parameters of the development programme and explain any deviations from standard requirements, where they exist. Restating specifications without that explanation is treated by assessors as a formal box-ticking exercise. The Clinical Overview (2.5) must justify the chosen dose and indications based on Module 5 data and explicitly name any unresolved safety questions. If assessors find such questions in the primary Module 5 reports themselves, confidence in the dossier drops immediately.
Logical Bridges Between Modules 3, 4, and 5
Module 3 splits into the substance section 3.2.S (general information, manufacture, impurity characterization, quality control, stability) and the finished product section 3.2.P (composition, pharmaceutical development, manufacture, control, stability). Module 4 consists of three major blocks: pharmacology (4.2.1), pharmacokinetics (4.2.2), and toxicology (4.2.3), with toxicology itself split into subsections for single-dose and repeat-dose administration.
Module 5 collects clinical study reports in Section 5.3: biopharmaceutic studies (5.3.1), pharmacokinetic studies using human biomaterials (5.3.2), human pharmacokinetic studies (5.3.3), pharmacodynamic studies (5.3.4), and, separately, efficacy and safety studies (5.3.5), which is where adverse event data belongs.
The quality of the connections between sections determines the integrity of a dossier far more than the total volume of files. Changing the active pharmaceutical ingredient (API) supplier in Section 3.2.S.2 triggers a chain of checks across the whole dossier. If the new supplier’s impurity profile changes, the substance characterization in Section 3.2.S.3 needs updating. An impurity above the qualification threshold moves the question to Module 4, which needs toxicological data on its safety.
If a process change affects the dissolution profile of the finished product, the expert body is entitled to request a bioequivalence study from Module 5. All conclusions from this chain feed into the Quality Overall Summary (2.3) and the Clinical Summary (2.7) in Module 2. The wording in the SmPC in Module 1 is updated last, once the scientific part has already been agreed.
Vertical linkage works the same way. An adverse event recorded in the clinical study reports of Section 5.3.5 must appear in the safety table of the Clinical Summary (2.7), then receive a risk assessment in the Clinical Overview (2.5), and finally appear in Section 4.8 of the SmPC. A break in this chain looks like this: an adverse event is present in the primary report and missing from the package leaflet. Assessors treat that kind of break as grounds to question how completely safety data has been disclosed.
The Technical eCTD Layer in the EAEU
The logic of the five modules describes the content of the dossier; the eCTD format describes its technical packaging. In the EAEU, this side of the question is governed by a separate act issued by a different body of the Commission: Decision of the Board of the Eurasian Economic Commission of 30 June 2017 No. 79, «On Requirements for the Electronic Form of Applications and Registration Dossier Documents Submitted During the Registration and Examination of Medicinal Products for Human Use.» This decision is easy to confuse with EEC Council Decision No. 79 of 2016: the latter sets out the Rules of Good Clinical Practice and has nothing to do with the electronic dossier format. The matching numbers between a Council decision and a Board decision often mislead specialists who cite «Decision No. 79» without specifying which body issued it.
Through this act, the Commission approved the technical schemas for two XML structures. The R.017 structure describes the data in the marketing authorization application. The R.022 structure describes the data of the registration file or registration dossier as a whole: the list of files, their types under the EEC classifier, and checksums.
Registration in the EAEU proceeds either through the mutual recognition procedure or the decentralized procedure. Under mutual recognition, one member state acts as the Reference State and conducts the review first, while the others become States of Recognition and confirm that outcome within their own territory. A single R.022 document cannot combine documents for different member states, so the applicant’s modules for each State of Recognition are kept isolated from one another within a single XML structure.
The lifecycle of documents within R.022 is managed through the operators New (first submission of a document), Replace (replacing a version on update, the most common operator), Delete (withdrawal of a document submitted in error), and Append (adding a fragment to an existing file). Current practice avoids the Append operator: it makes the dossier harder for the assessor to read, and replacing the whole file through Replace is preferred.
The technical layer does not stand apart from the content layer. The data in the R.017 structure comes from Section 1.2.1 of Module 1: the product name, dosage form, strength, and marketing authorization holder go into the machine-readable file straight from the same application filed in that section. A discrepancy between the text of the application and the R.017 data, a different spelling of the product name, for example, is logged by the regulator as a technical error before substantive review even begins. The Replace operator in R.022 is tied to a specific section too: when a GMP inspection report is updated, the file is replaced in Section 1.6.3 specifically, without rebuilding the whole dossier.
The industry is meanwhile preparing for the move to eCTD version 4.0, built on the HL7 RPS (Regulated Product Submission) standard. The old folder hierarchy of version 3.2.2 is giving way to an object-based model in which data is tied to its context of use, and a fixed directory tree stops being a mandatory principle of organization. The new architecture will let sponsors reuse the same document, an active substance master file, for example, across several dossiers without a physical resubmission, and promises two-way communication between the applicant and the assessor inside the submission structure. The EAEU has not announced a timeline for the move to eCTD 4.0, so for current submissions the priority remains correct work with the R.017 and R.022 structures in the present format.
Action Plan
Check the structure of Module 1 against Annex No. 1 to Decision No. 78. Do not use the EU or FDA template as a baseline. Pay separate attention to Sections 1.7, 1.8, and 1.10, where EAEU numbering departs from the logic familiar from ICH.
Map the language regime for every section of Module 1. Record where English is accepted without translation (Section 1.6.3) and where only a translated summary is required (Sections 1.10.1 and 1.10.3), so documents are not translated unnecessarily.
Check the cross-references between Module 2 and Modules 3-5 before submission. Every statement in the Quality Overall Summary and the Clinical Overview should point to a specific section of the primary data.
When a manufacturing process changes, trace the chain 3.2.S.2 → 3.2.S.3 → Module 4 → Module 5 → Module 2 and record in writing at which step the chain stopped and why.
Confirm which body issued a decision when citing EEC acts with matching numbers. EEC Council Decision No. 79 and EEC Board Decision No. 79 govern different matters, and a wrong reference can mislead colleagues or the expert body.
The transparency of the connections between modules determines the quality of a registration dossier more than the number of pages in it. A specialist who sees these connections in advance closes out an assessor’s comments at the preparation stage. That approach saves months compared with responding to a query after submission.
Regulatory Framework:
1. EEC Council Decision No. 78 of 3 November 2016, «On the Rules for Registration and Examination of Medicinal Products for Human Use» (as amended 26 November 2025)
2. Annex No. 1 to EEC Council Decision No. 78, «Requirements for Documents of the Registration Dossier (in the Common Technical Document Format)»
3. EEC Board Decision No. 79 of 30 June 2017, «On Requirements for the Electronic Form of Applications and Registration Dossier Documents Submitted During the Registration and Examination of Medicinal Products for Human Use»
4. EEC Council Decision No. 79 of 3 November 2016, «On Approval of the Rules of Good Clinical Practice of the Eurasian Economic Union» (referenced here for disambiguation)