Author Imran KT, Gore S, Giradkar P.
treatment of illness has been accomplished by administrating drugs to human body via various routes namely oral, sublingual, rectal, parental, topical, inhalation etc. Topical delivery can be defined as the application of a drug containing formulation to the skin to directly treat cutaneous disorders like acne or the cutaneous manifestations of a general disease like psoriasis with the intent of containing the pharmacological or other effect of the drug to the surface of the skin or within the skin. Semi-solid formulation in all their diversity dominates the system for topical delivery, but foams, spray, medicated powders, solution, and even medicated adhesive systems are in use, The delivery of a drug to a specific site, topical formulations are probably among the most challenging products to develop. An effective topical formulation needs to provide a stable chemical environment in a suitable dispensing container to accommodate multiple compounds that may have different, if not incompatible, physicochemical characteristics, once applied, a topical formulation must interact with the skin environment, which can influence the rate of the release of the compounds in order to achieve adequate skin absorption, The excipients themselves will exert additional physical effects on the skin, such as drying, occluding, or moisturizing, technology have brought a better understanding of the physics, chemistry, pharmacodynamic, and pharmacokinetics for drugs used to treat acne. These insights have resulted in new delivery systems that are capable of enhancing the efficacy, tolerability, and cosmetic acceptability of topical formulations Topical drug delivery offers the advantages of ease of delivery, a cooperative patient, increased compliance as well as the avoidance of first-pass metabolism, New drug delivery technology and penetration enhancers, There are important issues to consider as you contemplate development of a topical dermatological product. You may already have experience with oral or parenteral products, but there are challenges and issues which are unique to development of topical formulations, A topical formulation must be aesthetically pleasing, in addition to being both physically and chemically stable, and this may require numerous excipients. The formulation must allow for optimal penetration of the drug into the skin, a complex tissue. Skin pH is approximately 5.5; thus the pH of the formulation may change following application to the skin.
