Pain is everywhere. From a bump on the head, cuts and burns to headaches and broken limbs, the list is endless. We have all experienced pain in varying degrees. Pain treatment has not changed in decades. In this article, we explore dissolving microneedle patches for pain treatment.
Until recently, the medical profession recognized 2 types of pain: nociceptive and neuropathic pain.
Nociceptive pain is the most common, resulting from an injury or illness. Nociceptors are specialized nerve cells that receive input from your body and send a clear signal. For example, you hit your thumb with a hammer and a message is instantly sent to the brain that there is a problem – and your thumb throbs.
This type of pain tends to pass in time, but we occasionally need a painkiller to dull the discomfort. Analgesics, like paracetamol or ibuprofen are the first line of defense. Sometimes, a stronger painkiller like an opioid might be needed.
Neuropathic – often called chronic – pain results from damaged nerves in the pain signaling highway and is usually long-lasting. Chronic pain debilitates people and requires more aggressive painkillers and long-term treatment. As Goldberg and McGee note, “10% [of adults] are newly diagnosed with chronic pain each year.”
A New Category of Pain
The International Association for the Study of Pain (IASP) recently recognized a new category, called “nociplastic pain – pain that arises from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nociceptors or evidence for disease or lesion of the somatosensory system causing the pain.”
This new classification will lead to better insight into chronic conditions. The result will be more compassionate care, improved treatments, and better patient outcomes for those who suffer.
Traditional Treatment of Pain
How we treat pain has remained largely the same for decades. Common treatment includes liquids, tablets, or capsules taken orally as well as topical creams and gels. Stronger painkillers and local anesthetics are typically administered by injection. Injections are fast and effective, but mostly limited to hospital settings.
From analgesics to powerful painkillers taken orally, the body must process the medicine in what is known as ‘first pass effect’. As we metabolize a drug, its concentration is reduced and impacts on the liver are a concern. Additionally, “the first pass effect can also occur in the lungs, vasculature, gastrointestinal tract, and other metabolically active tissues in the body.”
We all process orally administered drugs differently. This impacts the drug load delivered into our bodies, which varies from person to person, prompting research into more efficient delivery methods. Transdermal drug delivery using dissolving microneedles (dMNs) – also known as micro array patches (MAPs) – is proving a highly effective solution.
An important element in drug delivery is patient compliance. It can be easy to skip a trip to the doctor for an injection. Oral dosing can be difficult for infants and older patients alike who often have trouble swallowing tablets. And while applying creams and gels is easy, they are less effective in crossing the skin barrier and delivering results. Easy-to-use dissolving microneedle patches for pain treatment will improve patient compliance and have better drug delivery.
Comparison of topical cream, transdermal patch, hypodermic needle and microneedle patch
|Topical cream||Transdermal patch||Hypodermic needle||Microneedle|
|Description||Emulsion/ emulgel/ cream/ ointments||Adhesive patch to be placed on the skin||Fine, hollow tube having a sharp tip with small opening at the end||Micron size needles are aligned on the surface of a small patch|
|Onset of action||Slow||Slow||Faster||Faster|
|Mechanism of drug delivery||Permeation through skin pores.||Drug has to cross stratum corneum barrier, thus poor diffusion of large molecules||Drug placed directly in the dermis||Bypass stratum corneum and drug placed directly into epidermis or dermis hence enhanced permeability|
Anesthetics – another drug class – create a complete loss of sensation to relieve pain. Local anesthetics, typical in minor procedures, numb a small area and the patient stays conscious. General anesthetics, used in more serious procedures, leave the patient unconscious and oblivious to pain.
Lidocaine has been the most common local anesthetic since the late 1940s. It takes effect in a few minutes, creating numbness from 30 minutes to 3 hours. The US Food and Drug Administration (FDA) approved Lidoderm, a 5% Lidocaine adhesive transdermal patch in the late 1990s. The large – 10 x 14 cm – patch must remain on the skin for 12 hours. But the dosage is weak and it is reported that “at least 95% (665 mg) of lidocaine will remain in a used patch.”
This and other barriers to efficient painkiller drug delivery has boosted research into delivering dissolving microneedle patches for pain treatment. New technologies improve drug delivery efficiency by providing an effective means for medicines to cross the skin barrier.
What is Microneedle/Micro-Array Patch Technology?
Although they have different names, microneedles and micro-array patches are essentially the same. They are small patches of tiny needles that pierce the thick outer layer of skin – stratum corneum – and deliver medicines into the body. Advanced bioengineering has demonstrated the effectiveness of dissolving microneedles (dMNs).
Learn about microneedles and how they work here.
Dissolving microneedle patches for pain treatment have several advantages. Studies confirm there is no first pass effect, as “transdermal delivery eliminates drug exposure to the GI [gastro intestinal] tract and first-pass metabolism, and ensures the sustained and controlled release of drugs.”
Microneedles allow safe self-administration, and the drug gets to work quickly. As a result, patient compliance improves. They have superior thermostability compared to traditional injectables thereby reducing cold chain and administration logistics. Another benefit is the elimination of needlesticks injuries and biohazardous waste associated with hypodermic needles.
Best of all – dissolving microneedles are painless.
Next-gen dissolving microneedle patches can deliver drugs with large molecular weight and/or hydrophilic compounds into the skin. Studies have recognized that “permeability enhancement of two to four orders of magnitude has been observed for small molecules like calcein and also for the relatively larger compounds like proteins and nanoparticles.”
Microneedles for Advanced Drug Delivery
Advanced drug formulations require advanced delivery mechanisms. Protein-based, DNA-based and other new therapeutic compounds can be unsuitable for injection and oral delivery.
Dissolving microneedles fill this void.
Different Routes of Drug Delivery
Dissolving Microneedles Patches for Pain Treatment to Deliver Lidocaine
Fast-acting painkillers are essential to manage both acute and chronic pain conditions. Dissolving microneedle patches for pain treatment to deliver Lidocaine, one of the most used painkillers, is the focus current research.
Commercially available lidocaine patches take 45 minutes to deliver an effect. In 2014, Futurity magazine reported National University of Singapore research demonstrating a conventional microneedle patch can deliver results starting 5 minutes after being applied on the skin.
SeriTech has raised the bar with the world’s first products based on the fast detaching dissolving microneedle (fddMN). In just 2 minutes, a SeriTech micro array patch painlessly penetrates the outer layer of skin and delivers active ingredients. The microneedles detach and start dissolving, releasing medicine into your system.
SeriTech is leveraging this technology to develop better dissolving microneedle patches for pain treatment. A system that easily delivers drugs faster into the body, will improve patient outcomes with rapid pain relief.
Microneedles for Neuropathic Therapy
Neuropathic – chronic – pain is caused by nerve damage. It is debilitating and often difficult to treat. Certain types of peripheral nerve injury generate persistent neuropathic pain, which can result from trauma, infections, inflammation, tumors, metabolic disease, or endocrine diseases.
Current chronic pain treatments have a variety of side effects. An analgesic dissolving microneedle delivering effective localized neuropathic pain management could be the solution. The potential impact for millions of sufferers is significant.
The SeriTech Solution
SeriTech continues R&D with its main partners into treatments for chronic pain. Using the fast detaching dissolving microneedle provides ease of use and is capable of delivering a range of treatments, from painkillers to skincare remedies.
SeriTech aspires, with its manufacturing, R&D and pharma partners to lead the shift in acute and chronic pain treatment away from oral administration to a range of highly effective micro array patches. Accurate dosing, measurable release patterns and targeted delivery are the hallmarks of the world’s first fast detaching dissolving microneedle.