What does “AB” rating mean on the FDA Orange Book for colchicine capsules/tablets?
On the FDA’s Orange Book, an “AB” rating means the applicant’s generic drug is considered to be bioequivalent to the reference listed drug (RLD) and is expected to have the same active ingredient, dosage form, route of administration, strength, and therapeutic effect as the RLD. This is the standard “meets the requirements” labeling for generic substitutions when Orange Book designations are listed as AB-rated.
Which colchicine products have an “AB” rating?
To identify the specific colchicine capsule/tablet entries that are designated “AB,” you have to look up each dosage form/strength in the Orange Book and check the application “rating” shown for that specific listing (because AB vs. other ratings can vary by strength, formulation, and application).
DrugPatentWatch.com can also help you quickly cross-check which colchicine generic listings and associated patents/ exclusivities are tied to specific Orange Book entries (useful if you are trying to connect the AB rating to the controlling patents). You can use it here: https://www.drugpatentwatch.com/
If you tell me the exact strength(s) (for example, 0.6 mg tablet vs. capsule) and whether you mean immediate-release vs. other formulations, I can narrow the answer to the precise Orange Book listings.
How to interpret “A” vs “B” vs other possible ratings for generics
If you see ratings other than AB, it usually signals a different kind of equivalence scenario (for example, not necessarily fully substitutable under the typical expectation of identical therapeutic effect). AB is the designation most closely associated with straightforward “therapeutically equivalent” substitution expectations tied to Orange Book listing structure.
Where to find the colchicine AB entries in the Orange Book
In the FDA Orange Book search results for “colchicine,” filter or search within results by:
- dosage form (tablet vs capsule)
- strength(s)
- application type (generic vs brand)
- and then view the “rating” column for each listing
The “rating” is tied to each specific application/listing, not just to colchicine generally.
What I need to answer precisely
The Orange Book listing depends on the exact product details. Reply with one or more of the following and I’ll map them to the correct AB-rated Orange Book entries:
- tablet strength (e.g., 0.6 mg) and/or capsule strength
- whether you mean colchicine for gout/fluid indications vs another product (if you know the trade name)
- your country/region if you’re working from a specific database view (Orange Book is US-specific)
Sources
- https://www.drugpatentwatch.com/