International Journal of Pharmaceutical Investigation, 2011, 1, 1, 4-9.
DOI: 10.4103/2230-973X.76721
Published: February 2011
Type: Review Article
Authors:
Inderjeet Singh
School of Pharmacy, University of Nottingham Malaysia Campus, 43500 Semenyih, Selangor, Malaysia
Andrew Phillip Morris
School of Pharmacy, University of Nottingham Malaysia Campus, 43500 Semenyih, Selangor, Malaysia
ABSTRACT
Transdermal drug delivery (TDD) is a technique that is used to deliver a drug into the systemic circulation across the skin. This mechanism of drug delivery route has many advantages, including steady drug plasma concentrations, improved patient compliance, elimination of hepatic fi rst pass, and degradation in the gastrointestinal tract. Over the last 30 years, many transdermal products have been launched in the market. Despite the inherent advantages of TDD and the growing list of transdermal products, one of the major drawbacks to TDD is the occurrence of inter- and intraindividual variation in the absorption of the drug across the skin. A majority of these variations are caused by biological factors, such as gender, age, ethnicity, and skin hydration and metabolism. These factors affect the integrity and the barrier qualities of the skin, which subsequently result in the variation in the amount of drug absorbed. The main objective of this review article is to provide a concise commentary on the biological factors that contribute to the variation in transdermal permeation of drugs across human skin and the available transdermal therapeutic systems that may reduce the variations caused by biological factors.
Keywords: Percutaneous permeation, Therapeutics system, Variation in skin absorption.