In its never-ending quest to provide timely guidance on bioequivalence requirements for generic versions of brand name products, today, the FDA published 29 new and 20 revised BE guidance recommendations in the pre-publication of Federal Register Notice (here) as well as on their website (here, hint: look for the newly added and revised links on the page).

Many of the new guidances for topical products (e.g., ammonium lactate topical cream and lotion, clindamycin vaginal gel) are relying on Q1, Q2, and Q3 in vitro bioequivalence testing. Other products like calcitonin salmon injection could qualify for a waiver of in vivo bioequivalence testing by including comparative characterization studies to support active ingredient sameness (a relatively new phrase you will see in many PSGs) which is especially important for complex active ingredients. There is clear evidence (as demonstrated by this new batch of PSGs as well as discussions at the recent AAM GRx+Biosims conference) that FDA has established in vitro criteria for many product types for which in vivo BE studies may have been required in the past. Technology, analytics, and science-based knowledge has enabled a reduction in regulatory burden for many such products.

Of the 20 revised PSGs, the one that is most interesting is guidance originally issued in draft in October 2008 which was issued as a revised draft is in this batch.  The product is Goserelin Acetate implant, EQ 10.8 mg base and, as yet, there are no generics approved for the branded Zoladex product which was first approved on December 29, 1989. While there is no indication that an ANDA has been filed, one might assume there must at least be interest in the product!

Please review the revised new and revised PSGs and determine whether you need to interact with the Agency for advice as to how to proceed if you have a development project underway and have already completed BE testing, a pending application before the Agency, or even an approved application to determine what impact the PGS will have on your product.