The animals were kept in these facilities for at least 1 week prior to the experiment and were fasted for at least 24h before commencing the experiment. Before administration, the abdominal hair was shaved using an electric clipper carefully and allowed to heal for 24h. The animals were divided into three groups randomly with four animals in each group [14]. The first group was applied Inhibitors,research,lifescience,medical with DE MDTS. A dose of 20μL

solution containing 1.4mg DE was delivered to the fixed area (2cm × 2cm) on the shaved skin of rats by a micropipette. The second group was treated with Fenli; it was an oral tablet product of DE sold in Chinese market. The drug was dissolved in ethanol, and 3mL drug solution containing 1.4mg DE was delivered by intragastric injection. The third group received Inhibitors,research,lifescience,medical 0.3mL DE solution containing

1.4mg DE via the tail vein. The injection solution was prepared as follows: L-arginine was dissolved by water for injection and then DE was added. After decolorizing with 0.1% active carbon and filtrating by 0.22μm membrane, this solution was sterilized at Inhibitors,research,lifescience,medical 115°C for 30min in a sealed ampoule. Blood samples were collected into heparinized tubes at the scheduled sampling time via retroorbital plexus using a sterilized glass capillary tube. After centrifugation for 3min at 17,800×g, the separated serum of 100μL was transferred into another neat tube and frozen at −20°C until the determination of DE concentration by UPLC-MS/MS analysis. Inhibitors,research,lifescience,medical The pharmacokinetic parameters such as peak plasma concentration during the dosing period (Cmax ) and time of peak plasma concentration (Tmax ), the area under the profile (AUC0→t), the half-life of elimination from plasma (t1/2), and the mean residence time (MRT) were calculated by noncompartment analysis following transdermal application using DAS 2.0 software. Absolute bioavailability F(%) was calculated from the following equation: F(%)=Akt inhibitor AUCoptimal  formulationAUCi·v×100%.

(6) Relative bioavailability F(%) was calculated from the following Inhibitors,research,lifescience,medical equation: F(%)=AUCoptimal  formulationAUCoral×100%. (7) In this study, the dosage we give to each rat was 1.4mg, AUCi·v, AUCoral, and AUCoptimalformulation were the AUC0→t for intranvenous, oral, and transdermal routs, respectively. 2.7. Egg-Albumin Induced Paw Edema in Rats Healthy unless female Sprague-Dawley rats weighing 200 ± 20g were divided into three groups (n = 6) [15]. Before treatment, the circumference of ankle joint of the right hind paw was measured as the zero time circumference. 2h after intragastric injection of Fenli (7.0mg/kg based on DE) and transdermal administration of DE MDTS (see Table 8) (7.0mg/kg based on DE), peripheral inflammation was induced by intraplantar injection of 10% egg-albumin solution (0.1mL) into the middle of the plantar surface of the right hind paw. The remaining group without drug treatment was used as the control group.