eCTD Granularity Best Practices

The granularity of an electronic submission refers to the level of hierarchy of the folders and files (or the smallest unit of detail within the eCTD tree structure). While the International Conference on Harmonisation sets granularity requirements, authors and publishers need not adhere to a one-size-fits-all approach.

Document granularity is decided on a case-by-case basis - and as is common practice in the eCTD industry - clarity and simplicity are paramount. The level of granularity in a submission will impact submission maintenance and Agency review. Electing the appropriate level of granularity requires foresight and experience assembling electronic submissions. Once a level of granularity is decided upon, switching later on in the lifecycle is a difficult and time-consuming proposition.

Lower levels of granularity can simplify dossier changes and updates, aid Agency review and approval, and advance lifecycle publishing. By comparison, greater granularity supports applications containing complex products.

Best Practices

  • Understand which sections of a submission are up to interpretation as it relates to granularity. The main decisions revolve around QOS in Module 2, certain portions of Module 3, and the construction of study reports in Modules 4 and 5.

  • Understand the advantages and disadvantages of increased granularity. Authoring in smaller sections streamlines future submission maintenance. However, it can also complicate review, approval, and assembly processes. Consider how likely a document is to change over time before making your ultimate decision

  • Verify that your EDMS supports your desired level of granularity.