TRANSDERMAL DRUG DELIVERY PATCHES:
Transdermal Drug Delivery system (TDDS) consists of a substrate coated with self adhesive mass along with a suitable drug. This novel drug delivery system is preferred now a days as it offers many advantages over traditional oral dosage forms.
Advantages of Transdermal Drug Delivery Patches:
It is preferred when oral drug administration is not possible because of profuse vomiting, acidity, ulcer in stomach or if the patient is unconscious.
When too many doses of a drug have to be taken orally, transdermal patches provide a more convenient alternative. There is no need to take a tablet every few hours. Just apply the patch and you are good to go.
Transdermal drug delivery patches offer drug absorption at a steady rate. There is no dump dosing, so no risk of toxicity or overdosing.
Drug absorption can be stopped at any time by just removing the patch.
Transdermal patches are the most sophisticated & convenient way of drug delivery. According to their application different types of patches include:
1. Locally acting transdermal patches:
These have a local action, i.e. it affects only the area where it is applied.
E.g. Lidocaine Patch acts locally by desensitizing nerve endings.
2. Systemically acting patches:
These patches deliver the drug via skin, and the drug gets absorbed into the blood stream. The drug then acts systemically like after an injection.
e.g. Diclofenac Transdermal Patch and Ketoprofen transdermal patch.
Diclofenac patch can be applied anywhere on the body, and it gets absorbed into the blood stream. It then relives pain systemically.
Systemically acting patches also include motion sickness patch having Promethazine Hydrochloride. Also called antiemetic patch, it stops nausea and vomiting upon application. It is used for motion sickness & travel sickness. Pain relief patches & Nitroglycerin patch can also be used in angina pectoris.
Nicotine patch is used to decrease nicotine dependence and to quit smoking.
Fentanyl patch is a strong pain relieving product.
3. Hot and Cold patches:
These work by Rubefacient and counter irritant action. Main application of these patches is to provide pain relief by stimulating the area where it is applied. These pain relief patches are used to relive lower back pain, joint & muscular pain, sprains, strains, etc.
e.g. pain relief patch with essential oils, Capsicum Plaster, Belladonna plaster, Lidocaine with menthol patch.
3. Hot and Cold patches:
1. If any drug allergy or sensitivity is known, that patch should not be used.
2. Used patches should be disposed off properly so that children & pets do not have access to it. If applied or swallowed, it may have serious side effects.
3. Only 1 patch should be applied at a time unless otherwise specified on the packaging.
4. The time limit for which a patch has to be applied should be followed.
For e.g. Lidocaine patch is recommended to be applied for 12hours, followed by a 12 hour “off” period.
5. If any skin reaction or irritation occurs, it must be discontinued and medical help should be taken.
6. In case of poisoning or over dose, contact your doctor or the poison control department immediately.