Access of HTB, main metabolite of triflusal, to cerebrospinal fluid in healthy volunteers

Application of an LC-MS/MS Method to a Urinary Excretion Study of Triflusal and its Main Metabolite 2-hydroxy-4-trifluoromethyl Benzoic Acid in Human Urine

Objective:

A validated liquid chromatography-tandem mass spectrometry method (LCMS/ MS) was established to simultaneously determine the concentration of triflusal and its main metabolite 2-hydroxy-4-trifluoromethyl benzoic acid(HTB) in human urine.

Methods:

The separation was performed on a Dikma C18 column using isocratic elution with acetonitrile-4 mmol/L ammonium acetate aqueous solution containing 0.3 % formic acid water (78: 28, V/V). The method involved extraction with methanol using protein precipitation. The precursor-toproduct ion transitions with multiple reaction monitoring was m/z 247.1→161.1, 204.8→106.7and 136.9→93.0 for triflusal, HTB and salicylic acid(IS), respectively. The method showed good linear relationships over the ranges of 0.08 to 48 μg/mL and0.5 to 50 μg/mL.

Results:

It was the first time that a urinary excretion study of triflusal capsule as oral. The cumulative urinary recovery showed 8.5% and 2.7% for triflusal and HTB, respectively.

Conclusion:

This method was successfully used for evaluating the pharmacokinetic properties of triflusal and HTB in urine in Chinese healthy subjects.

Population pharmacokinetic modeling of sustained release lithium in the serum, erythrocytes and urine of patients with bipolar disorder

PURPOSE

Lithium (Li), the first-line treatment of bipolar disorder, was first developed as an immediate-release form with a routine therapeutic drug monitoring 12 h after the last dose. In Europe, the most commonly prescribed form is a sustained release (srLi). Yet no pharmacokinetics (PK) study has been published of srLi, administered once a day, in adults. The present study describes srLi PK in the serum and erythrocytes of bipolar patients.

METHODS

To assess srLi PK, we studied prospectively 17 French bipolar patients on a median dose of 1000 mg (600-1600) for at least 2 years. Serum (S), erythrocyte (E) concentrations, and urinary (U) amount were collected over 8 h after 15 days of morning intake using monitoring electronic medical system (MEMs). Population PK parameters were estimated using the SAEM algorithm (MONOLIX 4.3.3 software).

RESULTS

Using a population approach, we built a PK population model of srLi including one S compartment (V_S = 23.0 L, Cl_S = 1.21 L h^-1), one E compartment (V_E = 64.7 L, Cl_SE = 3.63 L h^-1, Cl_ES = 9.46 L h^-1), and one U compartment (F = 0.62) and estimate the ratio of concentrations to Li in E over S at 0.38 with 27% between-subject variability.

CONCLUSION

This is a PK model of srLi once a day in bipolar patients using a population approach simultaneously describing Li concentrations in serum, erythrocytes, and urine which provide an estimate of the ratio of concentration in erythrocyte over serum and its between-subject variability (BSV).

Neuroprotective effect of triflusal and its main metabolite, 2-hydroxy-4-trifluoromethylbenzoic acid (HTB), in the postischemic brain

2-Hydroxy-4-trifluoromethylbenzoic acid (HTB) is a metabolite of triflusal (TF), and has been reported to exert anti-inflammatory effect. In this study, the authors investigated whether HTB has a neuroprotective effect against ischemic brain injuries. We showed that intravenous administration of HTB (5mg/kg) 30min before or 1, 3, or 6h after middle cerebral artery occlusion (MCAO) reduced brain infarct to 10.4±3.3%, 16.9±2.3%, 22.2±1.5% and 40.7±7.5%, respectively, of that of treatment-naive MCAO controls, and the therapeutic time window extended to 9h after MCAO (40.7±7.5%). Furthermore, HTB suppressed infarct formation, protected motor activities, and ameliorated neurological deficits more effectively than by TF or salicylic acid (SA). HTB markedly suppressed microglial activation and proinflammatory cytokines expressions in the postischemic brain and in BV2 cells and suppressed LPS-induced nitrite production by inhibiting IkB degradation. In addition, HTB suppressed NMDA-induced neuronal cell death more effectively than TF or SA in primary cortical neuron cultures. Together, these results indicate that HTB has multi-modal protective effects against ischemic brain damage that encompass anti-inflammatory, anti-excitotoxicity, and anti-Zn²⁺-toxicity effects.

Population pharmacokinetic and pharmacodynamic modeling of transformed binary effect data of triflusal in healthy Korean male volunteers: a randomized, open-label, multiple dose, crossover study

Background

Triflusal is a drug that inhibits platelet aggregation. In this study we investigated the dose-exposure-response relationship of a triflusal formulation by population pharmacokinetic (PK) and pharmacodynamic (PD) modeling of its main active metabolite, hydroxy-4-(trifluoromethyl) benzoic acid (HTB).

Methods

This study was a randomized, open-label, multiple-dose, two-period, two-treatment, comparative crossover design. All volunteers received a single oral loading dose of 900 mg of triflusal on Day 1, followed by a dose of 600 mg/day from Day 2 to 9. Using data from 34 healthy volunteers, 476 HTB plasma concentration data points and 340 platelet aggregation data points were used to construct PK and PD models respectively using NONMEM (version 6.2). As the PD endpoint was qualitative, we implemented binary analysis of ‘inhibition’ and ‘non-inhibition’ rather than using the actual value of the test. The final PK-PD model was evaluated using a visual predictive check (VPC) and bootstrap.

Results

The time-concentration profile of HTB over the entire dosing period was described by a one-compartment model with a first-order formation rate constant for HTB. Weight was selected as a covariate for clearance and volume of triflusal, respectively. The structure and the population estimates for triflusal PK were as follows: oral clearance (CL/F) = 0.2 · (weight/71.65)^0.845 L/h, oral volume of distribution (V/F) = 8.3 · (weight/71.65) L, and k_f = 0.341 h^-1. A sigmoid relationship between triflusal concentration and the probability of significant inhibition with shape factor was chosen as the final PD model. No time delay between concentration and response was identified. The final structure between predicted concentration and the probability of inhibition of platelet aggregation (IPA) relationship was as follows: Probability of . Thus, we concluded this relationship is more like quantal concentration-response relationship. The current dosing regimen was considered to be efficacious based on the EC₅₀ estimate of 84.9 μg/mL obtained in this study.

Conclusions

A PK and binary probability PD model of triflusal was successfully developed for Korean healthy volunteers. The model may be used to further prediction inhibition of platelet aggregation by triflusal.

Trial registration

Clinical Research Information Service (CRIS), KCT0001299 (Registered December 5, 2014)

A novel synthetic HTB derivative, BECT inhibits lipopolysaccharide-mediated inflammatory response by suppressing the p38 MAPK/JNK and NF-κB activation pathways

Activated microglia cells are well recognized as mediators of neuroinflammation, as they release nitric oxide and pro-inflammatory cytokines in various neuroinflammatory diseases. Thus, suppressing microglial activation may alleviate neuroinflammatory and neurodegenerative processes. In the present study, we synthesized and investigated the anti-neuroinflammatory effect of a novel HTB (2-hydroxy-4-trifuoromethylbenzoic acid) derivative in lipopolysaccharide (LPS)-stimulated microglial cells. Among the synthesized derivatives, the BECT [But-2-enedioic acid bis-(2-carboxy-5-trifluoromethyl-phenyl) ester] significantly decreased production of nitric oxide and other pro-inflammatory cytokines including tumor necrosis factor-α, interleukin-1β, and interleukin-6 in microglial cells. BECT also mitigated the expression of inducible nitric oxide synthase and cyclooxygenase-2 at both the mRNA and protein levels. Further mechanistic studies demonstrated that the HTB derivative inhibited phosphorylation of JNK and p38 mitogen-activated protein kinase and nuclear translocation of nuclear factor kappa-B in LPS-stimulated BV-2 microglial cells. Thus BECT, our novel synthesized compound have anti-inflammatory activity in microglial cells, and may have therapeutic potential for treating neuroinflammatory diseases.

Triflusal reduces dense-core plaque load, associated axonal alterations and inflammatory changes, and rescues cognition in a transgenic mouse model of Alzheimer's disease

Inflammation has been associated with the two classic lesions in the Alzheimer's (AD) brain, amyloid deposits and neurofibrillary tangles. Recent data suggest that Triflusal, a compound with potent anti-inflammatory effects in the central nervous system in vivo, might delay the conversion from amnestic mild cognitive impairment to a fully established clinical picture of dementia. In the present study, we investigated the effect of Triflusal on brain Abeta accumulation, neuroinflammation, axonal curvature and cognition in an AD transgenic mouse model (Tg2576). Triflusal treatment did not alter the total brain Abeta accumulation but significantly reduced dense-cored plaque load and associated glial cell proliferation, proinflammatory cytokine levels and abnormal axonal curvature, and rescued cognitive deficits in Tg2576 mice. Behavioral benefit was found to involve increased expression of c-fos and BDNF, two of the genes regulated by CREB, as part of the signal transduction cascade underlying the molecular basis of long-term potentiation. These results add preclinical evidence of a potentially beneficial effect of Triflusal in AD.

Triflusal: An Antiplatelet Drug with a Neuroprotective Effect?

Triflusal is a derivative of salicylic acid with a well-established platelet aggregation inhibitory profile. Its pharmacokinetic and pharmacodynamic properties differ, however, somewhat from those of acetylsalicylic acid. A number of recent experimental and clinical studies have shown that triflusal is a potentially useful choice in the treatment and prophylaxis of brain ischemia because of its antithrombogenic as well as neuroprotective effects. Its antithrombogenic effect has been demonstrated at the clinical as well as at the experimental level, while its neuroprotective effect has been shown only in experimental models. The drug interferes with thrombogenesis by inhibiting thromboxane synthesis and increasing the levels of cAMP and nitric oxide. Its neuroprotective action is the result of its antioxidant and antiinflammatory effects in brain tissue. From a clinical standpoint triflusal is similar in efficacy to acetylsalicylic acid in preventing stroke, but has less adverse effects, especially it is less likely to cause bleeding. Because of its pharmacodynamic properties and lower rate of adverse reactions, triflusal may be a useful alternative to acetylsalicylic acid in the prevention of stroke.

Triflusal

Triflusal (Aflen, Disgren, Tecnosal, Triflux) is a novel platelet antiaggregant with structural similarities to salicylates, but which is not derived from aspirin. It has similar efficacy to aspirin in patients with cerebral or myocardial infarction, but has a reduced risk of haemorrhagic complications. In addition, triflusal plus moderate-intensity anticoagulation has demonstrated efficacy when used as thromboprophylaxis in atrial fibrillation. As such, triflusal has a role in the primary prevention of cerebrovascular events in atrial fibrillation, and for the secondary prevention of cerebral and myocardial infarction, primarily as an alternative to aspirin in patients for whom aspirin is unsuitable.