A Comparison Study Using Microneedle, Transdermal Gel, and Tape Strip-Based Delivery of Caffeine Infused with Chemical Enhancers: Characterizations and Ex-vivo Study

The transdermal route is considered one of the most favourable routes of drug delivery over other conventional routes. The stratum corneum (SC) is the main barrier to the delivery of drugs by the transdermal route. Many strategies are employed to overcome SC barrier properties like lipid vesicles, permeation enhancers, physical methods, etc. The main objective of this research article was to explore and compare a few chemical penetration enhancers in combination with physical means like tape stripping and microneedle to enhance the transdermal permeation of caffeine. The transdermal gel of caffeine was prepared by dissolving the drug in distilled water containing various concentrations of chemical penetration enhancers, including Arlasolve DMI, ethanol, transcutol P and DMSO. Ex-vivo skin permeation and skin deposition studies were conducted on the transdermal gel alone and in combination with the microneedle or tape-stripping methods. The HPLC method analyzed the total amount of caffeine that permeated through the skin sample. The formulations containing Arlasolve DMI as a penetration enhancer showed the maximum drug penetration among all the penetration enhancers. A combination of microneedles with Arlasolve DMI showed the best skin permeation among all the methods tested. It was clear from the results that Arlasolve DMI would be a better option to use as a penetration enhancer in the dermatological formulations of caffeine in combination with a microneedle-based permeation enhancement method.