Pharmacokinetics and in vivo potency of soluble epoxide hydrolase inhibitors in cynomolgus monkeys.

BACKGROUND AND PURPOSE: Soluble epoxide hydrolase inhibitors (sEHIs) possess anti-inflammatory, antiatherosclerotic, antihypertensive and analgesic properties. The pharmacokinetics (PK) and pharmacodynamics in terms of inhibitory potency of sEHIs were assessed in non-human primates (NHPs). Development of a sEHI for use in NHPs will facilitate investigations on the role of sEH in numerous chronic inflammatory conditions. EXPERIMENTAL APPROACH: PK parameters of 11 sEHIs in cynomolgus monkeys were determined after oral dosing with 0.3 mg·kg(-1). Their physical properties and inhibitory potency in hepatic cytosol of cynomolgus monkeys were examined. Dose-dependent effects of the two inhibitors 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) and the related acetyl piperidine derivative, 1-trifluoromethoxyphenyl-3-(1-acetylpiperidin-4-yl) urea (TPAU), on natural blood eicosanoids, were determined. KEY RESULTS: Among the inhibitors tested, TPPU and two 4-(cyclohexyloxy) benzoic acid urea sEHIs displayed high plasma concentrations (>10 × IC(50)), when dosed orally at 0.3 mg·kg(-1). Although the 4-(cyclohexyloxy) benzoic acid ureas were more potent against monkey sEH than piperidyl ureas (TPAU and TPPU), the latter compounds showed higher plasma concentrations and more drug-like properties. The C(max) increased with dose from 0.3 to 3 mg·kg(-1) for TPPU and from 0.1 to 3 mg·kg(-1) for TPAU, although it was not linear over this range of doses. As an indication of target engagement, ratios of linoleate epoxides to diols increased with TPPU administration. CONCLUSION AND IMPLICATIONS: Our data indicate that TPPU is suitable for investigating sEH biology and the role of epoxide-containing lipids in modulating inflammatory diseases in NHPs.

Role of physical chemical properties in drug relay into skin compartments.

The ability of a drug to reach the interstitial fluid is an important aspect of drug efficacy - as a possible indicator of skin and cell compartment concentration. This overview addresses the relationship of the physical properties of several antibiotics to their ability to enter the interstitial fluid utilizing a cantharidin blister model. By collecting pharmacokinetic data for 12 antibiotics administered orally and 11 intravenously, we compared the fraction of drug that reaches the interstitial fluid (AUC(blister)/AUC(serum)) to partition coefficients. Following data analysis, we found no correlation (p = 0.98 and 0.09, respectively) between hydrophobicity and the ability to reach the interstitium. Both orally and intravenously administered antibiotics display a strong linear correlation (p < 0.001 and p = 0.006, respectively) in the total concentration found in the serum and interstitial fluid indicating that serum concentration may be an important factor in dictating interstitial fluid concentration. This correlation may prove useful in clinical application as a means of determining interstitial fluid concentration by measuring only serum levels.