Skin in the game: The benefits of transdermal drug delivery
European Pharmaceutical Manufacturer editor, Felicity Thomas, sits down with Sally Waterman, COO at Medherant to discuss the benefits of transdermal drug delivery and how industry developments and changes in patient needs are leading to a shift…
In order to keep pace with the changing requirements of patients and the ongoing challenge of adherence to medications, innovative drug delivery methods are a must. Not only are patients expecting more from their medication, but they are also expecting the delivery to be quick, painless, with fewer side effects and easy to implement at home.
A distinctive offering from Medherant is the transdermal drug delivery patch (TEPI Patch), which, last year, was awarded with the Excellence in Science & Technology Award at the Coventry Telegraph Business Awards.1
Now, transdermal delivery systems are not necessarily new, with the first — a scopolamine patch2for motion sickness — launching nearly 40 years ago. However, the industry has continued to view this segment as niche and with a specific set of limitations, leaving oral solid dosage and injectable solutions as the market mainstays.
Yet, further developments in transdermal delivery technology and changing needs of the patient population is perhaps starting to buck the familiar trends…
The main barriers…
The main barriers for transdermal delivery have been limitations in the drugs that can be formulated as a transdermal patch and difficulties penetrating the skin barrier.
However, thanks to the development of new technologies, such as better adhesives, nanoparticles, chemical permeation enhancers that can improve drug solubility, or other active approaches, like ultrasound or high-voltage electrical pulses, the options available for transdermal delivery are expanding.
A drug-in-adhesive patch
The TEPI Patch is a drug-in-adhesive patch that has been formulated with a novel adhesive, which Medherant has exclusively licensed from Bostik. “Through this unique adhesive we are able to provide multiple benefits,” explained Waterman.“The adhesive has a higher loading capacity so more drug, or drug plus excipients, can be incorporated into the patch, which means that a smaller and/or thinner patch can be produced, lower potency drugs can be formulated for transdermal delivery, or the delivery of the drug can be controlled via the inclusion of specific combinations of excipients, including permeation enhancers.
“Also, the patch has durable contact with the skin, which ensures comfort and reassures the patient that the correct amount of the drug will be delivered,” she continued. “However, it is still easy to remove and once in place there is no leakage of adhesive around the edges of the patch.”
Does this mean that the drug is actually bound into the adhesive? “No,” stressed Waterman, “it is simply dissolved among the polymers in the adhesive and seepage of the drug from the patch whilst it is stored is prevented via a transparent liner. The liner is removed prior to the patch being placed onto the skin; once applied the drug can then permeate from the adhesive into the skin.”
She went onto explain that the free base or acid of a drug is used in the adhesive rather than a salt, which facilitates its passage through the skin.
Beneficial for a range of patient groups
Are there specific patients that would truly reap the benefits of a transdermal delivery option? “Yes, transdermal delivery is of particular benefit for patients who struggle to swallow oral medications, those who do not like injections and those experiencing nausea or vomiting, for example,” Waterman stated. So, transdermal delivery using a patch is of particular benefit to patient groups, such as geriatrics and paediatrics, that have the potential for poor adherence rates if their treatment requires them to swallow their medication or be injected.
By using a transdermal route of administration, the drug can bypass the stomach, which could improve treatment efficacy and reduce side effects. “This is particularly helpful for drugs that have a significant impact on the gastrointestinal mucosa or for those that are poorly or variably absorbed by the but after oral administration or are subject to extensive metabolism in the liver,” she added.
“Furthermore, multiple drug administrations can be avoided as the drug can be delivered from a patch over an extended period of time — this also offers potential cost benefits,” said Waterman. “Compliance can also be improved by administering a drug as a transdermal patch. A health worker/carer could apply the patch easily to a patient who is unable to swallow or might forget to take their medication, such as those suffering with Alzheimer’s disease or other forms of dementia.”
Commercial availability
What is the current position of the product in terms of market readiness? “Our first product, an Ibuprofen TEPI Patch, will be tested in Phase I clinical studies over the summer of 2018. A Phase III safety and efficacy study in patients with acute sports injuries is planned for 2019. The product is expected to be available to patients in 2021,” Waterman revealed. “Subsequent products will also be patch formulations of currently approved drugs and will include treatments for chemotherapy-induced nausea and vomiting and pain associated with a surgical procedure as well as products for chronic CNS diseases.
“We expect to have at least three of our own products in clinical development in 2019/2020.”
References: