Transdermals Explained

    Q: I am tired of the side effects of oral medications. Please tell me a bit more about transdermal patch treatment and what it can be used for. N.I.

    A: DR SANDI NYE REPLIES: A high absorption rate, directly into the bloodstream, can be achieved with many substances that are delivered transdermally, without the risk of gastrointestinal degradation or other common oral-medicine-related side effects. ‘Patch-treatment’, which is becoming more and more popular, appears to be a safe, effective and convenient substance delivery option, for a wide range of disorders and conditions, demonstrating good patient acceptability and compliance.

    Transdermal patches allow application of a substance, such as a natural remedy or a medicinal drug, through the skin, with the aim of allowing sustained release and slow absorption of the active ingredients. Patches are generally designed to release their active components in two ways – either the ingredients are stored within a porous membrane, which allows slow absorption when applied to skin; or the actives are embedded in thin layers within the actual adhesive part of the patch, which melts through body heat and is subsequently absorbed through the skin.

    There are basically five different types of medicinal transdermal patches:

    • Single-layer drug in adhesive patch
    • Multi-layer drug in adhesive patch
    • Reservoir patch (unlike the first two types, the reservoir system has a separate drug layer)
    • Matrix patch (considered the safest)
    • Vapour patch (relatively new patches that release volatile essential oil vapours for up to six hours).


    On the up-side: Transdermals have the advantage of providing a controlled release of the active substance, often at specific sites or areas of injury or pain. So if you have a back-ache, a patch on the specific area of discomfort can deliver a dose of the treatment directly where it’s needed, rather than having to go through other body processes before reaching the target area. This targeted delivery also allows for more accurate delivery of the actives into the bloodstream, unlike topical creams, gels or lotions, where dosage can be difficult to control. The risk of systemic side effects is also considerably reduced, and patches are usually a pain-free method of administration.

    On the down-side: The main disadvantage to transdermal delivery systems is the innate barrier function of the skin. There’s also a molecular weight issue, since many molecules are simply too large to pass through intact skin. Although there are new technologies being investigated to allow transdermal delivery of larger molecules, insulin for example, cannot pass through the skin without modification, as the molecules are too big. Other factors such as the thickness of the stratum corneum, the hydration level of the skin, body temperature, existing or underlying skin disease or in- juries, as well as ethnic differences can all affect the absorption rate of transdermal medications.

    Some patch-drug ingredients need to be combined with alcohol or other permeation enhancers to increase skin penetration ability, which can cause skin irritation. Constant application of a patch, to the same site, can also cause irritation or in the case of nitro-glycerin patches, overwhelm the body. Despite these considerations, a wide variety of pharmaceuticals are now available in transdermal patch form.


    Some of the well-known medicated patches include: the nicotine patch; pain-control patches; anaesthetic patches; hormone patches; angina pectoris patches; hypertension patches; anti-inflammatory patches; motion sickness patches; vitamin B12 patches; various vitamin, mineral and herbal patches; anti-depression patch; ADHD patch for hyperactivity; Alzheimer’s patch; and osteoarthritis patches.

    Patches with aromatic essential oil-releasing vapours are available for the following conditions: respiratory congestion, insomnia, addiction, beauty/aesthetic, health and wellness, stress-reduction, libido enhancement.

    I hope this helps.

    Editor's note: Talking of glycerine, here us Dr Sandi's article Discover the Glory of Glycerine
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