When the first generic Concerta products came to market late in 2013, they were Orange Book "AB" rated to the brand name. This means they were classified as "bioequivalent" by the FDA and therefore, were substitutable with one another.
However, shorty after the launch of the generics, the FDA received numerous complaints regarding the products and their ineffectiveness when compared to the brand name product. In fact, between May 2013 and June 2014, the FDA received over 300 complaints in regard to two generic products manufactured by Mallinckrodt and Kudco.
After reviewing the situation, the FDA found that the two generic methylphenidate products listed above could potentially deliver the drug at a slower rate in some individuals when compared to the brand name. This slower rate could potentially change the desired effect of the drug in the user.
As a result, the FDA revoked the "AB" status from the two generics. While they are still available on the market, they are not considered bioequivalent to the brand name Concerta and cannot be substituted for it. In October 2016, the FDA proposed to remove both the Mallinckrodt and Kudco (now Kremers) products from the market. As of November 2017, they are still available however.
Currently, there are 4 FDA approved 'AB' rated generics to the brand name Concerta:
- Methylphenidate ER manufactured by Actavis
- Methylphenidate ER manufactured by American Health Packaging
- Methylphenidate ER manufactured by Mylan
- Methylphenidate ER manufactured by Trigen
Source: Clinical Pharmacology