Oral treatment of rodents with soluble epoxide hydrolase inhibitor 1-(1-propanoylpiperidin-4-yl)-3-[4-(trifluoromethoxy)phenyl]urea (TPPU): Resulting drug levels and modulation of oxylipin pattern

Epoxides from polyunsaturated fatty acids (PUFAs) are potent lipid mediators. In vivo stabilization of these epoxides by blockade of the soluble epoxide hydrolase (sEH) leads to anti-inflammatory, analgesic and normotensive effects. Therefore, sEH inhibitors (sEHi) are a promising new class of drugs. Herein, we characterized pharmacokinetic (PK) and pharmacodynamic properties of a commercially available potent sEHi 1-(1-propanoylpiperidin-4-yl)-3-[4-(trifluoromethoxy)phenyl]urea (TPPU). Cell culture studies suggest its high absorption and metabolic stability. Following administration in drinking water to rats (0.2, 1, and 5 mg TPPU/L with 0.2% PEG400), TPPU's blood concentration increased dose dependently within the treatment period to reach an almost steady state after 8 days. TPPU was found in all the tissues tested. The linoleic epoxide/diol ratios in most tissues were dose dependently increased, indicating significant sEH inhibition. Overall, administration of TPPU with the drinking water led to systemic distribution as well as high drug levels and thus makes chronic sEH inhibition studies possible.