Update on Approval History for Passive Skin Patches (1979-2020)

In 2015, I published a paper titled “Transdermal Product Development in the Age of QbD”. In that paper, I provided an accounting of all the prescription-only, FDA-approved drug patches as of 2015. Since a number of years have passed since then, I thought it would be appropriate to audit/update those data and revisit my assertion that novel patches (APIs not previously delivered to/through the skin) are approved by the FDA at a rate of about 1 patch every other year((A concept I hinted at as early as 2011 and first presented formally in “The Role and Implications of QbD in the Topical/Transdermal Drug Development Process”, AAPS Webinar, February 2014.)).

In the process of revisiting these data, I omitted active patches (iontophoretic and self-heating patches) and I also added several non-OTC, passive patches I had overlooked that were approved by the FDA, but not launched or never widely available. Consequently, the more narrowly focused count of prescription-only, passive patches approved by the FDA by 2015 was 63 (five more than the 58 I claimed at the time) which works out to about 7 months between approvals from 1979 to 2015.

In the five-and-a-half years since the original paper was published, 21 more patches were approved bringing the total to 84 as of April 2021((I worked on 16 of these projects or about 1 in 5.)). This means the average time between approvals since 1979 is now 1 month less than it was just 5½ years ago and the average lag between approvals since 2015 is only 100 days!

The chart below shows the updated graph for all passive patch approvals. Those marked in red are the projects in which I participated.

The original paper also contained a plot of the novel patch approvals (i.e., the subset of approvals for which the API was first delivered by a topical/transdermal patch). At the time of publication in 2015, I noted 24 novel patches with an approval rate of about one patch every other year. After double-checking the data, I found there were only 20 novel, passive patches approved as of 2015 which gives a rate of 1.8 years (22 months) between approvals from 1979 to 2015 (still about 1 patch every other year.) Since 2015, only one novel patch has been approved by the FDA (Secuado, asenapine transdermal system, 10/15/2019), but that is enough to continue the trend.

As of this writing, there are 21 novel, passive patches approved by the FDA over the last 42 years so the historic rate is still EXACTLY 2 years/patch.

The chart below shows all the novel API patches plotted at their respective approval dates and a broken line showing the slope of one approval every 2.02 years.

These data, of course, consider only the US market which is still (I believe) the largest market for commercial pharmaceuticals and is often the focus for product development even for developers outside the USA. Nevertheless, these data give us confidence that the field is just as active as it ever was–even as we approach half a century.

Ken Miller

Transdermal & Intradermal Drug Delivery Systems 2016

Pharma ED Resources Inc. is organizing

Transdermal and Intradermal Drug Delivery Systems, 2016 Advanced Design, Development, and Delivery of Skin-Mediated Therapies and Vaccines

September 12-13 at the Racquet Club of Philadelphia

I attended this conference last year for the first time and I really enjoyed it. It’s a beautiful, but intimate venue in the heart of Philadelphia. The speakers and the audience questions were all excellent and I can’t wait for the next one.

I have the honor and distinct pleasure of addressing the audience three times on Monday afternoon (I’m going to need a lozenge). First, I’m going to give a presentation on Product Development Trends: Insourcing and Outsourcing. Later, I’ve got some remarks on the recent FDA Draft Guidance on Assessing Adhesion with Transdermal Delivery Systems and Topical Patches for ANDAs. Hopefully, we can generate some lively debate on the pros and cons of the draft. Keeping with the regulatory theme, but casting a wider net, Michael Eakins and I will again host an open-forum discussion on Regulatory Considerations for TDD & IDD Systems. This was a really interesting session last year that showed this topic is just as relevant to product developers as it is to our regulatory affairs partners.

Check out the brochure on the Pharma ED Resources website and register here or contact me directly to see if you’re eligible for a discount.

If you have any interest in transdermal or intradermal systems, you really ought to be there.

Perspectives in Percutaneous Penetration-La Grande Motte, France

I’m heading for the South of France next week for the 15th International Conference on Perspectives in Percutaneous Penetration.

I look forward to this meeting for a number of reasons, but mostly because this is the meeting where I met, and continue to meet, the world’s most prominent researchers. (Some of whom I met at the 2nd PPP more than a quarter century ago). We’ve all learned a lot about the skin since then, but we’re still learning and that’s the point of the meeting.

If you’re going to be at the PPP in La Grande Motte next week, stop by and see me in the expo. I’d love to hear a little about what you’re up to and I might even be able to make a suggestion or two.

Au revoir!




Read the new article by Ken Miller

Available for free, unlimited access exclusively through ISYN Consulting.


“If one looks at the history of transdermal patch development as the discovery and identification of viable molecules, […] new molecules reach the transdermal market with the regularity approaching that of a clock that ticks once every two years.”

“The approach to transdermal product development before the QbD initiative was the same as that by which any complex product was developed from the time of the industrial revolution through the middle of the twentieth century. […] In my mind, it resembled the classic design houses of the auto industry (led by men like Enzo Ferrari, Harley Earl or, later, John DeLorian).”

“With increasing pressure to get equivalent products on the market; timelines were shortened, studies were limited and professional project management became part of transdermal product development leaving little room (or patience) for individual ‘style’. To survive and profit, companies had to have an efficient plan for transdermal product development in order to reach the market more than once.”

The full article is yours to download or access as often as you desire. Password: pilot

Transdermal Product Development in the Age of QbD

Transdermal patches: past, present and future

Well, it took a little longer than I anticipated, but the fine folks at Future Science’s Therapeutic Delivery now have the new issue (number 6) available online.

You can find a link to the issue here (Therapeutic Delivery).

The research articles are available to subscribers, but anyone can access my editorial Transdermal patches: past, present and future.

In Case You Missed It…

The Transdermal and Intradermal Drug Delivery Systems conference in Philadelphia was a great success.

Thanks to the sponsors, organizers and attendees for making this a diverse and fascinating event and I can’t wait for the next one!

In case you missed the conference, you can check out my slides at the link below.

Novel Patch Designs & Technologies

Be sure to check out the other speakers and talks from the brochure and follow Pharma Ed Resources for information on the next one!

I’ll be there!

Did you know?

Did you know most transdermal patches…

…are no thicker than a human hair?

…last longer than the pills they replace?

…with fewer side effects?

…no moving or electronic parts?

…and cost only pennies to manufacture?

Want to know more? Let’s talk about it.