Transdermal drug delivery by the use of a patch has several advantages, such as prevention of premature metabolism and accurate control of dose. An obstacle is the highly impermeable character of our skin. The delivery through mucous membranes in body parts such as mouth, nose, and eyes is much more effective. As mucosae are rich in body fluids, patches usually get wet, causing premature drug-release in unwanted directions.
Kyung Eun Lee, Ewha Womans University, Seoul, South Korea, and colleagues designed a patch with Janus character: a hydrophobic surface prevents wetting by body fluids and a hydrophilic surface facilitates the coating with drug, as well as enhances the adhesion. The team coated a polyester fabric with the hydrophobic polymer poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-heptadecafluorodecyl methacrylate) via initiated chemical vapor deposition (CVD). Subsequently, one side was rendered hydrophilic by base-catalyzed hydrolysis. The hydrophilic surface is then coated with a drug-loaded hydrogel.
This patch efficiently blocks fluid penetration from one side to the other in wet conditions and shows a higher permeation flux compared to a control patch.
- Application of Monodirectional Janus Patch to Oromucosal Delivery System,
Jae Bem You, Ah Young Choi, Jieung Baek, Myung Seok Oh, Sung Gap Im, Kyung Eun Lee, Hye Sun Gwak,
Adv. Healthcare Mat. 2015, 4, 2229–2236.