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# FDA Denies Purdue Petition on Potential Generic Butrans
- URL: https://www.fdaweb.com/fda-denies-purdue-petition-on-potential-generic-butrans/
- Published: 2017-03-10T12:00:00.000Z
- Updated: 2026-09-14T22:11:01.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5138173

FDA has denied a Purdue Pharma petition asking it to to ensure that applications for approval of follow-on products citing Purdue’s Butrans (buprenorphine) transdermal system as the reference-listed drug are supported by pharmacokinetic data establishing equivalent buprenorphine exposure over the entire seven-day dosing interval. “Absent such data,” the [petition](https://www.regulations.gov/contentStreamer?documentId=FDA-2016-P-3313-0001&attachmentNumber=1&disposition=attachment&contentType=pdf&ref=fdaweb.com) said, “there would be no basis for the agency to rely upon its previous findings of safety and efficacy for Butrans and, correspondingly, no basis to conclude that a follow-on product would provide the same clinical effect as Butrans.” Butrans is indicated for managing pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate.  
  
Specifically, the petition asked that FDA for any 505(j) or 505(b) application:

- apply bioequivalence criteria for partial area under the curve during each of the last three days of the seven-day dosing interval to ensure similar systemic exposure to buprenorphine and hence similar clinical response between the test and reference formulations;
- assess adhesion in accordance with a 6/2016 draft guidance on assessing adhesion with transdermal delivery systems and topical patches for ANDAs and the recently revised 10/2016 draft bioequivalence guidance for buprenorphine transdermal system for seven-day transdermal administration; and
- carefully evaluate irritation and sensitization potential in accordance with the applicable draft bioequivalence guidance.

In its [denial letter](https://www.regulations.gov/contentStreamer?documentId=FDA-2016-P-3313-0004&attachmentNumber=1&contentType=pdf&ref=fdaweb.com), FDA said it was rejecting the company’s arguments without comment because it has made no final determination on whether to approve or not approve any submission referencing Butrans. “In the case of NDAs or ANDAs referencing Butrans, FDA’s consideration of one or more applications will necessarily inform our decisions on the nature of the data and information necessary to support approval,” the agency said. “Therefore, we must determine whether it would be appropriate for us to take final agency action on the approvability of a specific aspect of a 505(b)(2) NDA or ANDA before taking final action on the approvability of the NDA or ANDA as a whole.”