Stop me if you’ve heard this before.
What would you say if you could receive shots painlessly over an extended period?
From people who have trouble swallowing pills to those living in remote areas, transdermal patches are a rapidly growing solution to the demand for accessible, self-administrative healthcare.
Having worked alongside many healthcare companies over the past three decades, Strouse is fearless in seeking new methods to design and build medical products.
After this review, you’ll have a basic understanding of transdermal patches, their different types, their materials, and how they’re manufactured so that you can explore the options available for transdermal product development.
What are Transdermal Patches?
Transdermal patches are stick-to-skin adhesives embedded with drugs or solutions transferred through the epidermis after prolonged skin contact.
An adhesive fixes the patch to the skin, and after a period, the transdermal solution will seep through the skin cells and enter the dermis and the bloodstream.
The most recognizable transdermal patches, popularized during the early 2000s, are nicotine patches. Other types include treatments for Vitamin C deficiency, CBD delivery, ADHD treatments, hormone deficiency, nausea relief, and even fragrance delivery or insect-repelling transdermal patches.
Transdermal patches are classified as combination products by the U.S. Food and Drug Administration (FDA) since they’re medical devices merged with a drug or biological product and require safety approval before being sold or distributed.
What is the Purpose of a Transdermal Patch?
Transdermal patches are an alternative method of delivering drugs, nutrients, or other solutions.
Rather than taking a pill or getting a shot, medications are increasingly adapted for transdermal applications. Some of the benefits include convenience, consistency, smoother dosing, avoiding digestive side effects, and improving patient experience.
What are the Different Types of Transdermal Patches?
Different transdermal patches are designed based on how the drug solution deploys.
Transdermal solutions can come in a liquid, gel, or crystallized solid form. Choosing a type of transdermal patch revolves around the most efficient skin transmission and the manufacturing feasibility.
At least six types of transdermal patches are available for different manufacturing and delivery methods. Selecting a type of patch to manufacture depends on the nature of your production set-up and the delivery requirements of your drug solution.
SINGLE-LAYER DRUG IN ADHESIVE PATCH
Single-layer transdermal patches are comprised of one layer: combined drug and adhesive. A single-layer patch is applied to the skin, where it sticks and deploys the drug.
MULTILAYER DRUG IN ADHESIVE PATCH
Multilayer transdermal patches are similar to the single-layer system in that adhesive layers release the drug, except BOTH adhesive layers contain drugs.
Typically, multilayer transdermal adhesives deploy solutions over a longer period of time because the width of the layers determines how quickly the drug reaches the skin.
Transdermal reservoirs are liquid layers containing the drugs which are gradually delivered to the skin through a rate-controlling membrane.
These reservoir patches allow for more controlled delivery rates, but the initial drug release can come in a slight burst. In addition, if the membrane is damaged, there is a risk of sudden release in the skin.
A transdermal matrix patch includes an adhesive polymer matrix containing the drug, which is gradually released into the skin.
Unlike the rate-controlling membrane in a reservoir patch, the formulation of its drug and polymer matrix dictates the rate of drug delivery. The active ingredient is distributed evenly throughout the patch, so there is less risk of accidental release.
Iontophoresis patches are medical devices that use small electrical currents to deliver charged substances to the skin. This substance is often applied directly to a designated spot on the patch before use and can consist of tap water for more mild uses.
Microneedle patches are transdermal patches with microscopic needles that penetrate the epidermis deep enough to help drugs enter the bloodstream.
Which Materials are Transdermal Patches Made From?
Material manufacturers often use stick-to-skin adhesives or bonding components to create transdermal patches.
Each layer of a transdermal patch might consist of a different material. For instance, the primary components are:
- Liner: Protects the adhesive, removed before application
- Drug/solution: Can be mixed with the adhesive or remain on its own, often in direct contact with the liner
- Adhesive: Joins together the patch itself while simultaneously adhering the device to the skin
- Membrane: Dictates the rate of transmission in multilayer and reservoir transdermal patches
- Backing: The protective outer layer guarding the rest of the patch from the environment
Since you know transdermal patches are made with different compositions, you should also recognize that different patches will require materials of varying strengths and abilities.
Companies supply specialized materials that protect the drug formulation while controlling its diffusion into the skin. For instance, 3M transdermal component products are categorized under the component you’re searching for.
It’s essential to consider the cleanliness of any medical products. When purchasing materials or using a converter, remember that you’ll want to search for a company with reputable Clean Room capabilities.
How are Transdermal Patches Manufactured?
Transdermal patches are manufactured in various ways depending on the patch type and the drug solution.
One way to manufacture transdermal patches is by coating the initial material with the solution BEFORE cutting and processing it. This has the benefit of potentially allowing a one-pass production process, but it isn’t always feasible given the nature of certain drugs that might limit the amount of handling.
Another transdermal patch manufacturing method is outsourcing the adhesive patch from a flexible material converter. The converter cuts out the shape of the adhesive and leaves an area to which the final solution can be applied AFTER the body of the product is created.
Lastly, it’s possible to acquire the adhesive patch from a converter while manufacturing your own secondary part loaded with the transdermal solution. This second part can then be attached to the converted adhesive to create your final product.
Regardless of how your transdermal patch is produced, you’ll wish to ensure that your design and chosen materials lend themselves to manufacturing in the most efficient manner possible. If you’re leaning towards multiple directions, you can get a free evaluation of your part drawing done by a flexible material converter: