Authorized generics (AG) are prescription drugs that are produced by the NDA holder and marketed under a private label, at generic prices. This circumstance typically presents itself when the NDA holder still has patent protection for the product on the market. Authorization of a generic occurs first as a contract between the NDA holder and the second party.
There are two potential regulatory paths for an AG. The most straightforward is the drug product produced as stated in the NDA (formulation, process, manufacturing site, etc.), the only change would be a new label for the generic product. This change can be an annual report item that the NDA holder files. There is no time delay with this pathway.
The second pathway is dependent on the specifics of the changes involved. In this scenario the second party manufactures the generic, ideally with the same formulation, process, testing, etc. The NDA holder adds the manufacturing site to the NDA. This addition can, in the worse case, be a Prior Approval Supplement (PAS) or depending on circumstances a Change Being Effected in 30 days (CBE30).
How long would it take for approval?
In the first pathway, the material can be marketed as soon as the label is approved. It must be submitted to the annual report for that year.
In the second pathway, the best alternative would be if the circumstances allow a CBE30, where 30 days after submission, the second party can ship product for use on the market unless the FDA responds otherwise.
In the second pathway, the PAS has no time commitment by the FDA reviewers, at a minimum today the agency is taking about 22 months for approvals, possibly longer.
What is the best strategy to change the API?
A change in the API will require the NDA holder to file a PAS. The best approach here would be to enter the market through the first pathway and then file the PAS for the API change. Again, there is no time commitment for a response by the agency, this could be 22 months or more due to the backlog at the FDA which is significant.
What would be the regulatory pathway to change the shape of the tablet?
A change in the tablet shape would require the NDA holder to file a PAS. See answer to question 3.
The following guidance documents should be helpful:
Changes to an Approved NDA or ANDA, CDER, April 2004
Changes to an Approved NDA or ANDA; Questions and Answers, CDER, January 2001