Latest Batch of FDA Product Specific Guidances Focus on Topical, Transdermal Drugs
To spur the development of complex generic drugs, the US Food and Drug Administration (FDA) on Tuesday issued 25 new and revised product-specific guidances detailing the agency’s expectations for generic drugmakers looking to bring copies of topical and transdermal delivery system (TDS) drugs to market.Among the documents are two new and 23 revised draft guidances for topical and TDS products administered via patches or extended release films.
The two new guidances provide recommendations for a topical capsaicin patch and a transdermal estradiol and norethindrone acetate film, while the revised guidances cover TDS and topical versions of drugs such as the buprenorphine, fentanyl, oxybutynin and lidocaine.
According to FDA Commissioner Scott Gottlieb, topical and transdermal drugs are not only more complex to manufacture than traditional drugs but are often harder to evaluate for bioequivalence.
“The therapeutic effect of these types of drugs does not necessarily correlate with the amount in the blood and can be more difficult to measure through the blood. They can raise other issues that make the traditional, and often simpler, metrics generally used to evaluate generic drugs and prove sameness difficult to employ,” he said.
Because of this, Gottlieb said, many TDS products often face little competition from generic equivalents.
Gottlieb said that TDS products represent an opportunity for generic drugmakers who could break into high-value market and generate profits while reducing healthcare costs.
“Any steps we can take to encourage the development of generic competitors for complex drugs may have an outsized impact on access and drug spending,” he said.
Alongside the product-specific guidances, FDA also released a revised draft guidance and another new draft guidance focused on assessing issues related to transdermal and topical drug delivery, such as adhesion, irritation and sensitization potential for abbreviated new drug applications (ANDAs).
Gottlieb Statement, FDA