Buprenorphine implants: a model for expedited development and approval of new drugs

Regulations for new drug approvals require stringent safety testing and efficacy trial programs. The approval process for generic drugs, however, is significantly streamlined. Bioavailability data can substitute for new rounds of efficacy trials, thereby both decreasing time to approval and reducing the costs required for new studies. This regulatory choice has not been available when generic drugs are offered in a controlled release format such as a subcutaneous depot, transdermal patch or implant. The purpose of this review is to suggest that the approval of generic drugs in inert controlled release envelopes should be eligible for similar regulatory relief. Proof for this concept is provided by the example of the numerous controlled release buprenorphine products. Buprenorphine is a generic opioid used since the 1980s in tablet form to treat pain and to treat opioid addiction. Long-acting, inert delivery vehicles for the drug have become available for the same indications. Safety and bioavailability profiles of the long-acting products are the same or improved over the parent product. A review of the long-acting drugs provides compelling evidence to recommend that generic drug-controlled release products may be eligible for alternative regulatory programs.