Steam bath, vibration, and thermal ablation administrations augment the release of tramadol HCl from transdermal patch and enhance the plasma concentration in rats

Abstract

Recently, transdermal drug delivery has become popular due to their numerous advantages. They offer non-invasive application and eliminate the first-pass metabolism. The skin membrane is sensitive to heat and vibration that these applications enhance the skin permeability resulting in increased bioavailability. This study aims to determine the effect of steam bath (STB), vibration (VIB) and thermal ablation (THAB) on systemic absorption of tramadol HCl and compare all applications with each other. After preparing of tramadol HCl patches, in vitro release tests followed by in vivo animal experiments were conducted. The patches were applied to 32 Wistar albino rats divided into four groups: No potential trigger effect (NPTE), STB, VIB, and THAB. STB, VIB and THAB were applied by purchased devices. One hour later, the patches were removed and plasma concentration of tramadol HCl was measured by UV-Vis spectrophotometry at 271 nm. When compared to the control group, calculated plasma tramadol HCl µg/mL concentration increased significantly in STB, VIB and THAB (p<0.001). Finally, as trigger effects, steam bath, vibration and thermal ablation (42°C) dramatically increased the absorption amount of tramadol HCl (42.1%, 37.2 % and 43.8 %, respectively). The percentage release of tramadol HCl increased significantly in investigation groups when compared to NPTE (p[removed]