CEP Application Procedure: The Five Stages, Explained

A CEP is not issued at the end of a waiting period. It is issued when five separate decisions have gone the applicant's way, and any one of them can send the file back to the start. Buyers who understand the sequence stop asking how long a certificate takes and start asking which stage a file is sitting in. That question has an answer. The first one usually does not.

What follows is the procedure as a sequence of decisions rather than a timeline, because timelines differ by substance, by dossier quality and by how quickly a deficiency letter is answered.

What a CEP actually certifies

A Certificate of Suitability states that a defined substance, made at a defined site by a defined process, can be used in a medicinal product in the European Union in place of the substance-specific documentation that would otherwise sit in the marketing authorisation dossier.

Three limits follow from that sentence, and they matter commercially:

• It is tied to a pharmacopoeial monograph. No monograph, no CEP. The substance then travels by a different route, usually an Active Substance Master File.
• It is tied to a site and a process. A second site is not covered by moving a drum; it is a change to the certificate.
• It is not an approval of the product. It says the substance is suitable for use against the monograph. What the finished product does with it is a separate matter.

The commercial value is straightforward: a holder can supply any number of marketing authorisation holders without each of them re-documenting the substance. That is why the certificate is worth more to a supply chain than any single customer relationship.

Stage one: pre-submission

Before a dossier exists, three questions decide whether the route is open at all.

Is there a monograph? For established bile acid substances the answer is usually yes, which is what makes the CEP route viable for UDCA and CDCA in the first place. For a derivative that no pharmacopoeia has described, the route closes and the work moves into an ASMF.

Is there a TSE risk? Materials of animal origin carry a transmissible spongiform encephalopathy question that has to be answered in the file, not after it. The answer shapes what the starting material section has to contain.

Is the process one site or several? Multi-site manufacture, including a step performed elsewhere, changes the shape of the application and, in some configurations, the type of assessment it receives. Applicants who discover this at stage three lose months.

EDQM also runs a pre-submission channel for questions about applicability and for substances where a monograph does not yet exist. Using it costs time once and saves it repeatedly.

Stage two: the dossier

The dossier is the applicant's work, and it is where most of the eventual delay is manufactured. It follows the CTD structure for a drug substance, with the sections that matter most being the ones that carry data rather than description.

Section	What it has to establish	Where files commonly fail
S.1 general information	Nomenclature, structure, site, applicant	Site naming inconsistent with the certificate request
S.2 manufacture	Process description, controls, starting materials	Starting material defined later than the process justifies
S.3 characterisation	Structure, impurities, origin of each impurity	Impurity list built from one batch, not from the process
S.4 specification	Release and shelf-life limits against the monograph	Additional tests inserted without justification
S.5 methods	Methods, validation, monograph applicability	Claiming a monograph method is unsuitable without data
S.6 reference standards	Source and qualification of standards used	Working standards with no traceability statement
S.7 packaging	Container closure in contact with the substance	Packaging changed in practice but not in the file

The section that decides more outcomes than any other is the statement of monograph applicability. The applicant has to walk through the monograph test by test and say, for each one, whether the published method is used as written, is used with a validated alternative, or is not applicable to this substance. A vague answer here generates a deficiency letter that costs a full clock-stop to resolve.

Stage three: validation

Validation is administrative and unforgiving. The file is checked for completeness and internal consistency before any scientific assessment begins. A file that fails validation does not enter the queue; it goes back with a list.

The failures at this stage are almost never scientific. They are inconsistencies: a site name spelled two ways, a batch number in a table that appears nowhere in the batch records, a specification limit in S.4 that contradicts the limit stated in S.5, a validation report referenced but not attached.

None of this is difficult to catch. All of it is easy to miss when a dossier is assembled from documents written at different times by different people.

Stage four: assessment and the clock-stop

Assessment is where the scientific argument is tested. A rapporteur reviews the file against the monograph and against the general expectations for the route, and issues questions. When questions are issued, the clock stops. It restarts when the applicant answers, not when the applicant decides to start answering.

Three features of this stage deserve attention.

The clock-stop is not a grace period. It is a period in which the application is exposed. A file sitting unanswered for months looks, from the outside, exactly like a file that has been abandoned, and buyers should treat it that way until shown otherwise.

The questions are specific. A deficiency letter usually names the section, the claim and the evidence it considers missing. Applicants who answer the question asked, with data, close the loop in one round. Applicants who rewrite the section in prose reopen it.

Inspection is conditional. Not every application triggers a site inspection, and an inspection being requested is not an accusation. It is a signal that something in the file cannot be resolved on paper.

Stage five: decision and what comes after

The outcome is a grant, a request for further information, or a refusal. A granted certificate lists the substance, the monograph it is assessed against, the manufacturing site, and any additional tests the applicant committed to beyond the monograph.

Two obligations continue after the grant, and both are frequently underestimated.

Changes to the process, the site, the specification or the starting material have to travel through the notification or variation route, depending on what changed. A change made in the plant and not in the certificate creates a gap that is invisible until an auditor stands in front of it.

Certificates also have a validity period and require renewal. A supply relationship built on a certificate that quietly lapsed is a supply relationship with an expiry date nobody wrote down.

What a buyer should ask

The question "do you have a CEP?" produces a yes or a no. Neither is very useful. Four better questions:

1. Which stage is the application in, and when was the last deficiency letter answered?
2. Is the clock currently running or stopped, and if stopped, since when?
3. Does the certificate cover the site that will make my material, and the process version currently in use?
4. When is renewal due, and who inside the organisation tracks it?

Answers to those four tell you whether you are buying from a holder or from someone hoping to become one. For how the certificate then fits against other market routes, see CEP, DMF or written confirmation; for verification of what you are handed, see how a CEP or GMP certificate is actually verified; and if the certificate is the reason you are considering a switch, adding a second API source sets out what the change actually costs.

Official sources for the procedure itself are maintained by EDQM and sit alongside the European Pharmacopoeia; the GMP expectations that apply once a certificate exists are in EudraLex Volume 4.

Frequently asked questions

Does a CEP replace a marketing authorisation?

No. A CEP is a statement about a substance and the site that makes it. The marketing authorisation belongs to the finished product and remains with its holder. The certificate removes the need to re-document the substance in each authorisation, which is a different function.

Can a CEP be granted for a substance with no pharmacopoeial monograph?

No. The certificate certifies suitability against a monograph. Where no monograph exists, the substance follows the Active Substance Master File route instead, and the technical work shifts from demonstrating compliance to establishing a specification that a regulator will accept.

What happens if a deficiency letter is not answered?

The clock stays stopped. In practice an unanswered file is treated as inactive, and a buyer should treat a long-stopped clock as evidence that the application is not progressing, regardless of what the supplier reports about intentions.

Is a site inspection a sign that something is wrong?

Not by itself. An inspection is requested when the file raises a question that documents cannot settle. It can follow a new site, a changed process or an inconsistency that needs to be seen rather than read.

How often does a CEP have to be renewed?

Certificates carry a validity period and require renewal before expiry. The renewal is a separate piece of work from routine change notification, and it is the one most often missed because it sits outside the normal document cycle.

Does a CEP cover more than one manufacturing site?

Only if the certificate lists those sites. Adding a site is a change to the certificate, not an internal decision. Material made at a site not named on the certificate is not covered by it, even if the process is identical. EDQM