When today's fashion world wants to know what we'll be wearing next year, the answer may have more to do with medical science and less to do with the whims of Italian designers. Thanks to advances in drug delivery and formulation technology, combined with the threat of patent expiration and diminishing sales of blockbuster drugs, those small, sticky skin patches are not just for smokers anymore. The once stagnant transdermal delivery market is picking up steam and is forecast to grow dramatically over the next few years.
The FDA approved a total of 35 transdermal products over the past 20 years, the major of which use passive transport that allows the drug to be subsequently absorbed into the skin via natural processes. Delivery of scopolamine, nicotine, estrogen, and fentanyl made up the bulk of sales, and the industry steered clear of what they considered to be extremely limited market potential with other drugs.
In recent years, however, great strides have been made in the application of "active transport" to assist and regulate the movement of drug molecules across the skin membrane. This opened up the field to a much wider range of drugs, such as those with high molecular weights or those requiring blood levels to be controlled. Penetration enhancers, microporation, electroporation, iontophoresis, and ultrasound are some of the methods currently being employed. New materials and advances in polymer technology have also paved the way for innovative new products. Improvements in solubility and diffusion, better adhesive polymers, the integration of hydrogels, enzyme films and biosensors have led to smaller patches, improved wear, and even products with diagnostic and monitoring capabilities.
These developments have led to a vastly increased market potential. The US market for transdermal products was $ 5.7 billion in 2006, and is forecast to grow to almost $ 8 billion by 2010. Some market analysts predict that the global market could reach as high as $ 32 billion by 2015.
In addition to new technology, another factor driving the upward market trend is the fact that the development time and cost for transdermal products is significantly less than that of conventional drugs. Average R & D for a typical drug is $ 500 million over 15 years, while for a transdermal drug development time is roughly 4-8 years and costs $ 10 million to $ 15 million. This has attracted a large number of specialty pharmaceutical companies to the field, which have chosen to create niches in transdermal delivery rather than pure generics.
The industry's efforts have paid off, as some new transdermal products have recently been approved by the FDA, including Neupro for Parkinson's disease; Daytrana for the treatment of ADHD; IONSYS, an iontophoretic transdermal delivery system for fentanyl, and Emsam, a transdermal patch for depression. A wide range of innovative transdermal products are currently in clinical development in the US for a variety of indications, including diabetes, migraine, herpes virus and infertility.
With the ever-present pressure on pharmaceutical companies to extend product lifecycles and replenish dwindling pipes, interest in transdermals will continue to grow. The recent profusion of over-the-counter products, such as tooth whitening strips, cold sore treatments, acne patches, wart removers, and herbal skin treatments has led to greater consumer awareness and acceptance of these dosage systems. Continued advances in technology and materials will likely ensure an even wider range of products spanning all the therapeutic areas. So the next time your doctor asks you to roll up your sleeve do not be surprised if, instead of a needle, you're stuck with a patch.