Simultaneous Quantitation of a Novel α1/ß1-Blocker TJ0711 and Its Two Metabolites in Dog Plasma Using LC-MS/MS and Its Application to a Pharmacokinetic Study after Intravenous Infusion.

TJ0711∙HCl, which is a novel α1/ß1 adrenoceptor blocking agent with a ratio of 1:1 for α1/ß1, is designed to treat and prevent perioperative hypertension. M1 and M3 were identified as important metabolites in vitro for either antihypertension activity or the major metabolite production. In order to obtain a pharmacokinetic profile of both TJ0711 and its metabolites, a rapid, selective, and reliable LC-MS/MS method was developed and validated for simultaneous determination of TJ0711 and two metabolites in beagle dog plasma via efficiently separating two interferential metabolites M16 and M4 from M1 and M3, respectively. Chromatographic separation was achieved on a Waters CORTECS C18⁺ column (2.1 × 100 mm, 2.7 µm). The mass spectrometric detection was carried out in positive ion MRM mode with ESI⁺ source. Protein precipitation was used in sample preparation and provided good recovery without a matrix effect. Good linearity was observed at the ranges of 0.5⁻100 ng/mL for TJ0711 and M3, 0.1⁻20 ng/mL for M1. Additional validation results were within the acceptance limits followed U.S. FDA guidelines for bioanalytical method validation. This method was successfully applied to an intravenous infusion pharmacokinetic study of TJ0711 at dosing rates of 3, 6, and 12 µg/kg/min in anesthetized beagle dogs for the first time. TJ0711 and its two metabolites exhibited effective proportionality in the dosage of 3 to 12 µg/kg/min. Neither TJ0711 nor its metabolites showed significant differences in pharmacokinetic parameters such as t1/2, CL, and Vss among three dose groups.

Accurate determination of a novel vasodilatory ß-blocker TJ0711 using LC-MS/MS: Resolution of an isobaric metabolite interference in dog plasma.

A rapid, robust and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for bioanalysis of TJ0711, a novel vasodilatory ß-blocker in dog plasma. This assay is able to chromatographically separate TJ0711 from its isobaric metabolite as well as glucuronide conjugates. Chromatographic separation was achieved on a Welch Ultimate-XB C18 column (2.1 × 100 mm, 3 µm). The analyte and internal standard (propranolol) were extracted from plasma by liquid-liquid extraction using ethyl acetate. The mass spectrometric detection was carried out in positive ion multiple reaction monitoring mode. Good linearity was obtained over the concentration range of 0.5-500 ng/mL (r > 0.99) for TJ0711. Moreover, the method had good accuracy (RE ranging from -2.70 to -0.32%) and precision (RSD < 7.55%). TJ0711 was stable in dog plasma for at least 6 h at ambient temperature, for at least 30 days at -20°C and after three freeze-thaw cycles. This method was successfully applied to a preclinical pharmacokinetic study and the results demonstrated linear pharmacokinetics of TJ0711 over a dose range from 0.03 to 0.3 mg/kg. No significant gender differences were observed in TJ0711 plasma pharmacokinetic parameters.

Influence of dose and route of administration on the enantioselective pharmacokinetics of TJ0711 hydrochloride in rats.

The enantioselective pharmacokinetics of TJ0711 hydrochloride were studied in rats given different doses of rac-TJ0711 hydrochloride via intravenous and oral routes. R- and S-TJ0711 hydrochloride were both rapidly absorbed, and the average AUC0-∞ of R-TJ0711 hydrochloride was greater than that of S-TJ0711 hydrochloride after intragastric administration, with an R/S AUC ratio 1.11 and 1.35 for 30 and 50 mg/kg dose group, respectively. In contrast, the average AUC0-∞ of R-TJ0711 hydrochloride was smaller than that of S-TJ0711 hydrochloride after intravenous injection, with an R/S AUC ratio 0.57 and 0.73 for 10 and 20 mg/kg dose group, respectively. R-TJ0711 hydrochloride plasma half-lives were shorter than those of S-TJ0711 hydrochloride for all groups. AUC0-4h and Cmax between the two enantiomers were significantly different after oral administration of 50 mg/kg dose of the racemate, while no significant differences between the two enantiomers were found for all the pharmacokinetic parameters of the 30 mg/kg dose group. Significant differences between the two enantiomers were detected for nearly all the pharmacokinetic parameters after intravenous administration, except for the VZ of 20 mg/kg dose group. This study suggests that dose and route of administration will influence the enantioselectivity in the pharmacokinetics of TJ0711 hydrochloride in rats.

TJ0711, a novel vasodilatory ß-blocker, protects SHR rats against hypertension induced renal injury.

Previous studies suggested that ß-blockers with adjunctive α1-blocking activities warrant renoprotective function other than the therapeutic effect on hypertension. The current report is designed to dissect the role of TJ0711, a novel ß-blocker with a 1:1 ratio for the ß1/α1 blocking activities, in renoprotection in SHR rats. It was noted that TJ0711 possesses similar potency for control of blood pressure as that of Carvedilol. However, TJ0711 is much more potent in terms of protecting SHR rats against hypertension induced renal injury. Specifically, SHR rats treated with 20mg/kg/day of TJ0711 manifested significantly lower levels for urine albumin and total protein. In line with these result, TJ0711 treated rats displayed much less severe pathological changes in the kidneys. Mechanistic studies revealed that TJ0711 improves kidney perfusion during the course of hypertensive insult by enhancing eNOS expression through suppressing inflammatory cytokine secretion. TJ0711 also attenuates Vasohibin-1 expression to prevent HIF-1α from signal-induced degradation, and by which it promotes HO-1 expression to protect SHR rats against oxidative stress induced by hypertension in the kidneys. Together, our data suggest that TJ0711 possesses higher potency for renoprotection while manifesting the similar effect on hypertension therapy as Carvedilol.

Stereoselective HPLC Assay of TJ0711 Enantiomers by Precolumn Derivatization with GITC Using UV Detection and Its Application in Pharmacokinetics in Rats / 华中科技大学学报（医学）（英德文版）

the quantitative determination of TJ0711 enantiomers in rat plasma, and it can be used in pharmacokinetic studies.