Shashank Jain on formulation for drug delivery via the skin

What are the major benefits of delivering drugs via the skin?

Drug delivery through the skin can provide site-specific application while reducing first-pass metabolism and systemic side effects.¹ Consequently, patient compliance and pharmacological response can be improved. For example, anti-inflammatory drugs like NSAIDs are typically prescribed via the oral route. However, due to extensive first-pass metabolism, most NSAIDs have poor oral bioavailability.² Furthermore, NSAIDs are associated with severe gastrointestinal side effects such as bleeding and perforation of the intestinal wall. In the US alone, it is estimated that approximately 75,000 people are hospitalised each year due to the gastrointestinal side effects of NSAIDs.² In this regard, compared to the oral route, topical NSAIDs have shown similar therapeutic efficacy but with minimal side effects. The skin route can also be effectively used for extended or sustained drug delivery. For instance, ACZONE gel 5% is a topical acne product that contains both dissolved as well as undissolved drug. During skin application, dissolved drugs can readily cross the skin layer to provide immediate effect, while un-dissolved drug dissolves in sebum over time to provide a prolonged effect. Along with extended or sustained drug delivery, controlled delivery can be achieved by membrane-controlled transdermal patches.³ This can provide steady-state blood levels with reduced side effects and lower drug dosing.