Nemaura to debut 48-hour transdermal pain patch
The company is headquartered in Loughborough, UK, and was founded in 2005; it has already won awards due to the drug delivery method developed, in its Micro-Patch technology, to administer solid dose therapeutics, such as vaccines.
With its diclofenac transdermal patch, it builds on the company’s previous work to deliver treatments to patients with central nervous systems disorder – it is currently awaiting US Food and Drug Administration’s decision on its marketing authorisation application for its use with patients living with Alzheimer’s disease.
Transdermal drug delivery patches are being actively explored for a number of different treatment options and in-PharmaTechnologist (IPT) spoke to Nemaura’s CEO, Faz Chowdhury (FC), about the company’s soon-to-be-unveiled product, as well as the interest the industry is taking in such drug delivery methods.
IPT: What is the Diclofenac gel patch?
FC: The patch is based on a novel formulation that has shown improved speed and extent of absorption for a given surface area of skin. It is intended to be applied directly above or in very close proximity to the tissue area that requires pain relief.
IPT: How are the patches applied and how is the 48-hour period of pain relief achieved?
FC: The patch size may be as small as 3cm by 3cm, and multiple patches could be applied to the required areas, in the same way a gel would be applied to multiple areas as needed. The patch needs only be applied for a period of 3-4 hours, and our studies show a depot of drug forms below the skin which then gradually releases over a period of 48 hours, therefore negating the need for any further application of the product.
IPT: What advantages do transdermal patches provide over standard drug delivery?
FC: The key advantage we see, in this specific example, is that a user would on average apply a gel to the skin several times a day. In this case, a single application could provide pain relief for up to two days. This is a major benefit for the user, and the relief should be constant and one would expect the efficacy to be better than a gel.
IPT: How is the patch more effective than a gel?
FC: With gel, one applies a very thin coating on the skin and rubs it into the skin. The gel can then be rubbed off on clothing and provides a generally tacky surface for debris to accumulate – after an hour or so there isn’t much left on the skin, and what is left is very thinly spread. If the gel is so thinly spread then how much actually penetrates the skin? You need a very strong diffusion gradient to enable a drug to penetrate the skin, meaning you need a slab of gel and it needs to stay in position for a few hours at least. In addition, when it is so thinly spread and it is being absorbed into the skin, it most likely gets picked up by the skin's microcirculation very rapidly and, as a result, it never gets a chance to dive deep into the tissue where it really needs to go.
In reality, it is well known that most of the benefit one gets from rubbing a gel on the skin is from the massaging action and, where menthol is used, from the cooling effect on the skin. Whereas we have a system that actually focuses the drug in a specific region of the skin and, as a result, it has the power to provide efficacious pain relief.
IPT: Are there broader advantages over other types of medications, such as oral drugs?
FC: Yes, let’s say you are given antibiotics and told take a single dose, three times a day – to an average person that means breakfast, lunch and dinner. In other words, three doses that were designed to deliver the right amount of drug when taken at eight-hour intervals have all been taken in less than 12 hours! That is not good, as you are getting too much drug in your bloodstream in the first 12 hours and too little in the last 12 hours. With patches, you get a constant supply of drug, almost drip-fed in throughout the period you wear the patch (some patches last for up to seven days), and so you are always getting the right amount of drug.
IPT: Are there any limiting factors for this type of drug delivery?
FC: There are a small number of drugs (numbering less than 22) currently on the market in patches. The reason for this is that most drugs do not have the right properties, potency or molecule size to be able to penetrate the skin. The reality is if all drugs did have the right properties, they would probably all be in patches.
IPT: Are you seeing greater interest in this type of delivery from the pharma industry?
FC: I wouldn’t say pharma companies are showing a greater interest as such, simply because most drugs can’t be delivered in patch form but, where they can be, there is certainly an appetite to explore this route.