The results indicated that the DE MDTS showed reproducible amounts of the formulation per actuation. Table 9 Evaluation of per actuation content for DE MDTS (mean ± SD; n = 6). Rodents have a signaling pathway thinner stratum corneum and higher hair follicles density than human skin, so it may overestimate

the permeability of drugs in human when using rodent’s skin as model. However, the recent research indicated that Sprague-Dawley Inhibitors,research,lifescience,medical rat was a useful model for predicting human skin permeability with low interindividual variations and similar permeating rate (with twofold difference) [38]. In this experiment, the pharmacokinetic studies were conducted in rats for intravenous, transdermal, and oral routs. Inhibitors,research,lifescience,medical The mean plasma concentration-time of DE after IV, transdermal, and oral administration was presented in Figure 7. A summary of the pharmacokinetic parameters was shown in Table 10. As seen in Figure 7, the plasma concentration of IV group decreased promptly after drug administration. For the oral and transdermal administration group, the plasma DE concentrations increased to the peak level after administration;

thereafter, the plasma concentrations gradually declined. The peak plasma concentration of DE MDTS group Inhibitors,research,lifescience,medical was 11.23μg/mL at 6.5h, which decreased gradually to 5.05μg/mL at 24h. For the oral administration group, the peak plasma concentration was 23.88μg/mL at 1.5h, while it deceased to 3.07μg/mL at 24h. The result Inhibitors,research,lifescience,medical indicated that DE MDTS showed a more sustainable plasma concentration-time profile compared with oral administration group. The absolute bioavailability of DE MDTS was 37.45%. And the relative bioavailability was 62.19%. Figure 7 In vivo absorption profiles of DE after IV, oral, and transdermal administration in rats (mean ± SD; n = 4). Table 10 Pharmacokinetic parameters of dexketoprofen after IV, oral, and transdermal administration in rats (mean ± SD; Inhibitors,research,lifescience,medical n = 4). The experiment involving egg-albumin induced paw edema in rats was used to compare the anti-inflammatory performances of DE MDTS and Fenli. The hind paw edema-time curve was shown in Figure 8. After

stimulation by the short-acting inflammatory agent, egg-albumin, the hind paw exhibited marked swelling at 0.5h, which then decreased gradually to recovery over the next few hours for the DE MDTS and Fenli group. For the control and group, the swelling degree reached its peak level at 1h then decreased gradually over the next few hours. At the end-point 6h of observing, the swelling degree of the Fenli, DE MDTS, and control group was 0.00 ± 0.02, 0.10 ± 0.11, and 0.87 ± 0.21, respectively. As far as comparison of the Fenli with the DE MDTS group was concerned, the former exhibited less edema from 1 to 3h (P < 0.05), while both groups showed a comparable anti-inflammatory effect at 6h. Figure 8 Anti-inflammatory effects of DE MDTS and Fenli on egg-albumin induced rat hind paw edema (mean ± SD; n = 6).