Médicament topique

A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes including creams, foams, gels, lotions, and ointments. Many topical medications are epicutaneous, meaning that they are applied directly to the skin. Topical medications may also be inhalational, such as asthma medications, or applied to the surface of tissues other than the skin, such as eye drops applied to the conjunctiva, or ear drops placed in the ear, or medications applied to the surface of a tooth. The word topical derives from Greek τοπικός topikos, "of a place". Topical drug delivery is a route of administering drugs via the skin to provide topical therapeutic effects. As skin is one of the largest and most superficial organs in the human body, pharmacists utilise it to deliver various drugs. This system usually provides a local effect on certain positions of the body. In ancient times, people used herbs to put on wounds for relieving the inflammatory effect or as pain relievers. The use of topical drug delivery system is much broader now, from smoking cessation to beauty purposes. Nowadays, there are numerous dosage forms that can be used topically, including cream, ointment, lotion, patches, dusting powder and much more. There are many advantages for this drug delivery system - avoiding first pass metabolism which can increase its bioavailability, being convenient and easy to apply to a large area, being easy to terminate the medication and avoiding gastro-intestinal irritations. All these can increase the patient compliance. However, there are several disadvantages for this system - causing skin irritations and symptoms like rashes and itchiness may occur. Also, only small particles can pass through the skin, which limits the choice of drugs. Since skin is the main medium of topical drug delivery system, its conditions determine the rate of skin penetration leading to affecting the pharmacokinetics of the drug.