IDdb selects only pharmaceutical patents.
Patents are chosen for inclusion based on their pharmaceutical relevance, according to certain selection criteria. Patents falling outside these criteria are not included in the database.

IDdb does not cover patent families.
For a significant invention, patent applications will normally be made with a number of issuing authorities. This gives rise to a family of equivalent patents for the same invention. IDdb will include a record of the first publication in a family which we receive, and will then purposely exclude coverage of further equivalents.

In particular, this means that there are relatively few US patents in IDdb. The other authorities covered by the database publish patent applications, whereas a US patent is not usually published until it is granted. The granted US patent will usually therefore appear after an equivalent application from another authority has been published, and so will not be included in IDdb.

The patent is too old.
Our main patent monitoring service, Patent fast-alert, began publication in late 1990. Patents from before this date will not be found in IDdb.

The patent is from a country we don't cover.
IDdb monitors patents from five authorities, namely the Patent Cooperation Treaty, European Patent Office, United States Patent and Trademark Office, Japanese Patent Office and United Kingdom Patent Office. This monitoring gives us coverage of virtually all pharmaceutical inventions. However, patents from other authorities are not covered.