Trans-eyelid distribution of epinastine to the conjunctiva following eyelid application in rabbits.

PURPOSE: To reveal the penetration of epinastine, an anti-allergic ophthalmic agent, into the eyelid and its distribution to the conjunctiva after administration of a cream formulation on rabbit eyelid skin. STUDY DESIGN: Experimental study. METHODS: Rabbits were treated with 0.5% epinastine cream on hair-shaved eyelids, followed by preparation of eyelid tissue slices to determine spatial tissue distribution of epinastine by liquid chromatography-tandem mass spectrometry (LC-MS/MS) quantification using laser-microdissected tissues and desorption electrospray ionization mass spectrometry imaging (DESI-MSI). In addition, following either eyelid application of 0.5% epinastine cream or ocular instillation of 0.1% epinastine eye drops, concentration-time profiles of epinastine in the palpebral conjunctiva and bulbar conjunctiva were determined using LC-MS/MS. RESULTS: Laser microdissection coupled with LC-MS/MS analysis detected high concentrations of epinastine around the outermost layer of the eyelid at 0.5 h post-administration that gradually diffused deeper into the eyelid and was distributed in the conjunctival layer at 8 and 24 h post-administration. Similar time-dependent drug distribution was observed in high-spatial-resolution images obtained using DESI-MSI. Epinastine concentrations in the conjunctival tissues peaked at 4-8 h after administration of 0.5% epinastine cream and then decreased slowly over 72 h post-administration. In contrast, epinastine concentrations peaked quickly and decreased sharply after epinastine eye drop administration. CONCLUSION: After the application of epinastine cream to the eyelid skin, epinastine gradually permeated the eyelid. The compound was retained in the conjunctiva for 8-24 h post-administration, indicating that epinastine cream is a promising long-acting formulation for treating allergic conjunctivitis.

ABCB1 C3435T, G2677T/A and C1236T variants have no effect in eslicarbazepine pharmacokinetics.

Eslicarbazepine acetate is a third-generation anti-epileptic prodrug quickly and extensively transformed to eslicarbazepine after oral administration. Reduction in seizure frequency in patients managed with eslicarbazepine is only partial in the majority of patients and many of them suffer considerable ADRs that require a change of treatment. The P-glycoprotein, encoded by the ABCB1 gene, is expressed throughout the body and can impact the pharmacokinetics of several drugs. In terms of epilepsy treatment, this transporter was linked to drug-resistant epilepsy, as it conditions drug access into the brain due to its expression at the blood-brain barrier. Therefore, we aimed to investigate the impact of three ABCB1 common polymorphisms (i.e., C3435T, or rs1045642, G2677A or rs2032582 and C1236T or rs1128503) in the pharmacokinetics and safety of eslicarbazepine. For this purpose, 22 healthy volunteers participating in a bioequivalence clinical trial were recruited. No significant relationship was observed between sex, race and ABCB1 polymorphism and eslicarbazepine pharmacokinetic variability. In contrast, ABCB1 C1236T C/C diplotype was significantly related to the occurrence of ADRs: one volunteer with this genotype suffered dizziness, somnolence and hand paresthesia, while no other volunteer suffered any of these ADRs (p < 0.045). To the best of our knowledge, this is the first study published to date evaluating eslicarbazepine pharmacogenetics. Further studies with large sample sizes are needed to compare the results obtained here.

Bioequivalence and switchability of generic antiseizure medications (ASMs): A re-appraisal based on analysis of generic ASM products approved in Europe.

The safety of switching between generic products of antiseizure medications (ASMs) continues to be a hot topic in epilepsy management. The main reason for concern relates to the uncertainty on whether, and when, two generics found to be bioequivalent to the same brand (reference) product are bioequivalent to each other, and the risk of a switch between generics resulting in clinically significant changes in plasma ASM concentrations. This article addresses these concerns by discussing the distinction between bioequivalence and statistical testing for significant difference, the importance of intra-subject variability in interpreting bioequivalence studies, the stricter regulatory bioequivalence requirements applicable to narrow-therapeutic-index (NTI) drugs, and the extent by which currently available generic products of ASMs comply with such criteria. Data for 117 oral generic products of second-generation ASMs approved in Europe by the centralized, mutual recognition or decentralized procedure were analyzed based on a review of publicly accessible regulatory assessment reports. The analysis showed that for 99% of generic products assessed (after exclusion of gabapentin products), the 90% confidence intervals (90% CIs) of geometric mean ratios (test/reference) for AUC (area under the drug concentration vs time curve) were narrow and wholly contained within the acceptance interval (90%-111%) applied to NTI drugs. Intra-subject variability for AUC was <10% for 53 (88%) of the 60 products for which this measure was reported. Many gabapentin generics showed broader, 90% CIs for bioequivalence estimates, and greater intra-subject variability, compared with generics of other ASMs. When interpreted within the context of other available data, these results suggest that any risk of non-bioequivalence between these individual generic products is small, and that switches across these products are not likely to result in clinically relevant changes in plasma drug exposure. The potential for variability in exposure when switching across generics is likely to be greatest for gabapentin.

Simultaneous measurement of epinastine and its metabolite, 9,13b-dehydroepinastine, in human plasma by a newly developed ultra-performance liquid chromatography-tandem mass spectrometry and its application to pharmacokinetic studies.

Epinastine is an antiallergic drug with high selectivity for histamine receptors. It has been reported that 9,13b-dehydroepinastine is present as a metabolite in vivo in humans, but there was little information about their pharmacokinetics (PKs) in humans. Although several analytical methods have been reported for epinastine analysis in different matrices, none are available for its metabolite. Therefore, the purpose of this study was to develop an analytical method to simultaneously measure epinastine and its metabolite, 9,13b-dehydroepinastine, in human plasma samples using an ultra-performance liquid chromatography-tandem mass spectrometer. Analytes were separated on a C18 column. Quantification of this analysis was performed on a triple-quadrupole mass spectrometer. Chromatograms showed high sensitivity, selectivity, and resolution with no interference with plasma constituents. Calibration curves for both epinastine and 9,13b-dehydroepinastine in human plasma were 0.1-50 ng/ml and displayed excellent linearity with correlation coefficients (r2 ) >0.99. The developed analytical method satisfied the criteria of international guidance and was validated. The method could be successfully applied to pharmacokinetic studies of epinastine and, for the first time, the metabolite kinetics of epinastine to 9,13b-dehydroepinastine in humans after oral administration of 20 mg epinastine hydrochloride tablets. Our study is expected to be useful in future studies such as dosage settings and clinical pharmacotherapy.

Pharmacokinetic Comparison of Epinastine Using Developed Human Plasma Assays.

The purpose of the study was to develop two new methods, HPLC-UV and UPLC-MS/MS, for quantifying epinastine in human plasma and to compare pharmacokinetic (PK) parameters obtained using them. Even in the same sample, there may be a difference in the quantitative value of drug depending on the assay, so that minor changes in PK parameter values may affect drug dose and usage settings. Therefore, selection and establishment of analytical methods are very important in PK studies of drugs, and a comparison of PK parameters according to analytical methods will be vital. For this study of PK parameter change, we newly developed two methods, HPLC-UV and UPLC-MS/MS, which are most commonly used to quantify epinastine concentrations in human plasma. All developed methods satisfied the international guidelines and criteria for successful application to PK study of 20 mg epinastine hydrochloride tablets after oral administration to twenty-six humans. A comparison of these two methods for in vivo analysis of epinastine was performed for the first time. This comparison study confirmed that different dose and usage settings might be possible based on PK parameters calculated using other analyses. Such changes in calculated PK parameters according to analytical methods would be crucial in the clinic.

Development and validation of a specific and sensitive LC-MS/MS method for determination of eslicarbazepine in human plasma and its clinical pharmacokinetic study.

In this work, we developed and validated the specific, sensitive and simple LC-MS/MS method for quantification of eslicarbazepine in human plasma. The analyte samples were prepared through a simple one-step protein precipitation method by acetonitrile. The chromatographic separation was operated on an economical Hanbon ODS-2 C18 column (150 mm × 2.1 mm, 10 µm) with isocratic elution using 10 mM ammonium acetate containing 0.01% formic acid and acetonitrile (72:28, v/v) as the mobile phase at the flow rate of 0.5 mL/min. The mass quantification was carried on the multiple reaction monitoring (MRM) of the transitions of m/z 255.1 → 194.1 for eslicarbazepine and m/z 446.1 → 321.1 for glipizide (the internal standard), respectively. The established method was validated with acceptable specificity, linearity, accuracy, precision, extraction recovery, matrix effect and stability in accordance with FDA regulations. At last, the validated method was successfully applied to determination of eslicarbazepine in human plasma obtained from clinical study.

In vitro and in vivo performance of epinastine hydrochloride-releasing contact lenses.

A number of drug-releasing contact lenses are currently being studied to address issues inherent in eye drops as a drug delivery method. In this study, we developed epinastine hydrochloride-releasing daily soft contact lenses for treatment of allergic conjunctivitis and examined their in vitro and in vivo performance. Preformed soft contact lenses with/without ionic functional groups were soaked in a solution of epinastine hydrochloride in phosphate-buffered saline to prepare epinastine hydrochloride-releasing soft contact lenses. Among these contact lenses with different ionicities, anionic lenses demonstrated the maximum, relatively linear epinastine hydrochloride release, in vitro. The amount of epinastine hydrochloride release was directly proportional to the concentration of the epinastine hydrochloride solution used to prepare the contact lens. The epinastine hydrochloride-releasing anionic soft contact lens also demonstrated prolonged drug release and significantly greater efficacy compared with epinastine hydrochloride eye drops 12 h after treatment, in vivo. Further studies are required to determine the appropriate amount of epinastine hydrochloride to be contained in the anionic soft contact lenses.

[Antiepileptic drugs]. / Farmacos antiepilepticos.

We report the most notable pharmacokinetic and pharmacodynamic characteristics of the antiepileptic drugs commercialised in the last four years (eslicarbazepine acetate, brivaracetam and perampanel). Their efficacy and safety are analysed in open-label clinical trials, which are the ones that reproduce their use in everyday life, without the rigid protocols used in clinical trials.

TITLE: Farmacos antiepilepticos.Se refieren las caracteristicas farmacocineticas y farmacodinamicas mas destacadas de los farmacos antiepilepticos comercializados en los cuatro ultimos años (acetato de eslicarbacepina, brivaracetam y perampanel). Se analiza su eficacia y tolerabilidad en estudios clinicos abiertos, que son los que reproducen su utilizacion en la vida diaria, sin los protocolos rigidos de los ensayos clinicos.

Exposure-safety and efficacy response relationships and population pharmacokinetics of eslicarbazepine acetate.

OBJECTIVES: Eslicarbazepine acetate (ESL) is a once-daily (QD) oral antiepileptic drug (AED) for focal-onset seizures (FOS). Pharmacokinetic (PK) and pharmacodynamic (PD) models were developed to assess dose selection, identify significant AED drug interactions, and quantitate relationships between exposure and safety and efficacy outcomes from Phase 3 trials of adjunctive ESL. METHODS: Eslicarbazepine (the primary active metabolite of ESL) population PK was evaluated using data from 1351 subjects enrolled in 14 studies (11 Phase 1 and three Phase 3 studies) after multiple oral doses ranging from 400 to 1200 mg. Population PK and PD models related individual eslicarbazepine exposures to safety outcomes and efficacy responses. RESULTS: Eslicarbazepine PK was described by a one-compartment model with linear absorption and elimination. The probability of a treatment-emergent adverse event (TEAE; dizziness, headache, or somnolence) was higher with an initial dose of ESL 800 mg than with an initial dose of ESL 400 mg QD. Body weight, sex, region, and baseline use of carbamazepine (CBZ) or lamotrigine were also found to influence the probability of TEAEs. Eslicarbazepine exposure influenced serum sodium concentration, standardized seizure frequency, and probability of response; better efficacy outcomes were predicted in patients not from Western Europe (WE; vs WE patients) and those not taking CBZ (vs taking CBZ) at baseline. CONCLUSIONS: Pharmacokinetic and PK/PD modeling were implemented during the development of ESL for adjunctive treatment of FOS in adults. This quantitative approach supported decision-making during the development of ESL, and contributed to dosing recommendations and labeling information related to drug interactions.

Population Pharmacokinetics and Exposure-Response Analyses of Eslicarbazepine Acetate Efficacy and Safety in Monotherapy of Partial-Onset Seizures.

Eslicarbazepine acetate (ESL) is a once-daily oral antiepileptic drug (AED) indicated for partial-onset seizures (POS). ESL pharmacokinetics (PK) and exposure-response analyses were supported by 2 phase 3 conversion to ESL (1200, 1600 mg) monotherapy studies. The PK model development included 10 phase 1-2 studies (ESL 600-1200 mg daily). Seizure diaries were completed daily; subjects exited if seizures worsened. Exposure-response models were developed for time to study exit, probability of seizure freedom, time to first occurrence of dizziness, headache, and nausea; serum sodium levels were explored. A 1-compartment model with first-order absorption/elimination described ESL PK. Clearance and distribution volume were significantly related to body weight and sex. Higher eslicarbazepine minimum concentration (Cmin ) and use of 1 baseline AED were associated with significantly lower risk of study exit, whereas eslicarbazepine Cmin was a significant predictor of seizure freedom during the last 4 weeks of monotherapy. Eslicarbazepine exposure and the time to first occurrence of adverse events were not related. A shallow negative relationship described the relationship between change from baseline in serum sodium level and eslicarbazepine exposure. Eslicarbazepine apparent clearance and distribution volume estimates were similar to those reported for ESL adjunctive therapy. Dose adjustment based on body weight was not required. The time to study exit and probability of seizure freedom during the last 4 weeks of monotherapy were weakly related to eslicarbazepine exposure. Because the first occurrence of adverse events or hyponatremia were also not significantly related to eslicarbazepine exposure, dose adjustment using plasma eslicarbazepine concentrations is not supported.

Evidence for a pharmacokinetic interaction between eslicarbazepine and rosuvastatin: Potential effects on xenobiotic transporters.

INTRODUCTION: Patients with partial-onset seizures and comorbid cardiovascular disease may concomitantly receive eslicarbazepine acetate (ESL), an antiepileptic drug, and rosuvastatin, an HMG-CoA reductase inhibitor. This study evaluated the effect of multiple-dose ESL on the pharmacokinetic (PK) parameters of a single dose of rosuvastatin in healthy subjects. METHODS: This was a Phase I, single-center, fixed-sequence, open-label study. Healthy subjects received two treatments, in sequence. Treatment A: a single 40mg oral dose of rosuvastatin on Day 1, followed by a washout period (Days 1-4); treatment B: titration of ESL (400-800mg once daily) on Days 5-18, followed by ESL 1200mg once daily on Days 19-35, with a single dose of rosuvastatin (40mg) on Day 32. Subjects then entered a 2-week follow-up period. Plasma concentrations of rosuvastatin were quantified for PK analyses. Safety and tolerability were assessed throughout the study. RESULTS: Thirty-three healthy subjects were enrolled and 30 completed the study. Mean rosuvastatin (standard deviation) t1/2 was similar when rosuvastatin was used concomitantly with ESL and when it was used alone (26.5 [16.3]h, and 22.4 [9.5]h, respectively). The geometric least squares mean ratios (90% confidence intervals) of rosuvastatin exposure levels between rosuvastatin used concomitantly with ESL and rosuvastatin used alone were as follows: Cmax, 64.0% (55.9-73.3%); AUC(0-∞), 63.0% (57.1-69.4%); and AUC(0-last), 60.9% (55.2-67.1%). Concomitant use of ESL and rosuvastatin was generally well tolerated. CONCLUSIONS: Rosuvastatin exposure was 36-39% lower with steady-state administration of ESL, potentially due to reduced oral bioavailability of rosuvastatin. Consequently, when rosuvastatin is used with ESL, a rosuvastatin dose adjustment may be necessary if a clinically significant change in lipids is noted.

Pharmacokinetic variability, efficacy and tolerability of eslicarbazepine acetate-A national approach to the evaluation of therapeutic drug monitoring data and clinical outcome.

BACKGROUND: Eslicarbazepine acetate (ESL) is a new antiepileptic drug (AED), still insufficiently studied regarding pharmacokinetic variability, efficacy and tolerability. The purpose of this study was to evaluate therapeutic drug monitoring (TDM) data in Norway and relate pharmacokinetic variability to clinical efficacy and tolerability in a long-term clinical setting in patients with refractory epilepsy. METHODS: This retrospective observational study included TDM-data from the main laboratories and population data from the Norwegian Prescription Database in Norway, in addition to clinical data from medical records of adult patients using ESL for up to three years, whenever possible. RESULTS: TDM-data from 168 patients were utilized for assessment of pharmacokinetic variability, consisting of 71% of the total number of patients in Norway using ESL, 2011-14. Median daily dose of ESL was 800mg (range 400-1600mg), and median serum concentration of ESL was 53µmol/L (range 13-132µmol/L). Inter-patient variability of ESL was extensive, with 25-fold variability in concentration/dose ratios. Additional clinical data were available from 104 adult patients out of the 168, all with drug resistant focal epilepsy. After 1, 2 and 3 years follow-up, the retention rate of ESL was 83%, 72% and 64%, respectively. ESL was generally well tolerated as add-on treatment, but sedation, cognitive impairment and hyponatremia were reported. Hyponatremia (sodium <137mmol/L) was present in 36% of the patients, and lead to discontinuation in three. CONCLUSION: Pharmacokinetic variability of ESL was extensive and the demonstration of usefulness of TDM requires further studies. In patients with drug resistant focal Epilepsy, the high retention rate indicated good efficacy and tolerability. Hyponatremia was observed in one third of the patients. The present results point to a need for individualization of treatment and TDM may be useful.

Eslicarbazepine acetate: its effectiveness as adjunctive therapy in clinical trials and open studies.

Eslicarbazepine acetate (ESL) is a once-daily antiepileptic drug that is approved as adjunctive therapy in adults with focal-onset seizures. Following oral administration, ESL is rapidly metabolized to its active metabolite, eslicarbazepine, which acts primarily by enhancing slow inactivation of voltage-gated sodium channels. The efficacy and safety/tolerability of ESL in the adjunctive setting were established in a comprehensive Phase III program (n = 1702 randomized patients) and this evidence has been supported by several open studies (n = 864). ESL treatment has demonstrated improvements in health-related quality of life, in both randomized clinical trials and open studies. ESL has also been shown to be usually well tolerated and efficacious when used in the adjunctive setting in elderly patients. The effectiveness of ESL as the only add-on to antiepileptic drug monotherapy has been demonstrated in a multinational study (n = 219), subgroup analyses of which have also shown it to be efficacious and generally well tolerated in patients who had previously not responded to carbamazepine therapy. Open studies have also demonstrated improvements in tolerability in patients switched overnight from oxcarbazepine to ESL. Due to differences in pharmacokinetics, pharmacodynamics, and metabolism, there may be clinical situations in which it is appropriate to consider switching patients from oxcarbazepine or carbamazepine to ESL.

The Impact of Pharmacokinetic Interactions With Eslicarbazepine Acetate Versus Oxcarbazepine and Carbamazepine in Clinical Practice.

BACKGROUND: Eslicarbazepine acetate (ESL) is a new anti-epileptic drug (AED) chemically related to oxcarbazepine (OXC) and carbamazepine (CBZ) and is increasingly used in clinical practice. The purpose of the study was to investigate 2-way pharmacokinetic interactions between ESL and other AEDs as compared to OXC and CBZ. METHODS: Anonymous data regarding age, gender, use of AEDs, daily doses and serum concentration measurements of ESL, OXC, CBZ and lamotrigine (LTG) and other AEDs were retrieved from 2 therapeutic drug monitoring (TDM) databases in Norway. Drugs were categorized according to their known potential for interactions. Concentration/dose (C/D) ratios were calculated. RESULTS: Data from 1100 patients were available. The C/D ratios of ESL and OXC were unchanged in combination with enzyme-inducing AEDs or valproate (VPA). The C/D ratio of CBZ decreased by 40% and 22% in combination with other enzyme-inducing AEDs or VPA, respectively, pointing to an increased clearance. ESL demonstrated no significant enzyme-inducing effect on LTG metabolism although there was a 20% and 34% decrease in the C/D ratio of LTG in combination with OXC and CBZ, respectively. CONCLUSIONS: Possible pharmacokinetic interactions have been studied for ESL as compared to OXC and CBZ. The pharmacokinetics of ESL is not affected by enzyme-inducing AEDs or VPA and does not affect the metabolism of LTG in contrast to OXC and CBZ. The study demonstrates the value of using TDM databases to explore the potential for pharmacokinetic interactions of new AEDs.

A Pharmacokinetic Study Comparing Eslicarbazepine Acetate Administered Orally as a Crushed or Intact Tablet in Healthy Volunteers.

The relative bioequivalence of crushed versus intact eslicarbazepine acetate (ESL) tablets (800 mg) administered orally in healthy adults was evaluated in an open-label, randomized, 2-period crossover study with a 5-day washout between treatments. Sample blood levels of eslicarbazepine and (R)-licarbazepine were determined; pharmacokinetic parameters were derived for eslicarbazepine. Bioequivalence was established if the 90% confidence intervals (CIs) for the geometric mean treatment ratios of eslicarbazepine AUC(0-∞) and Cmax were within the prespecified 80%-125% range. Twenty-seven subjects in the intent-to-treat population (n = 28) completed both treatment periods. Eslicarbazepine exposure measures were similar for crushed versus intact ESL tablets: average Cmax , 11 700 versus 11 500 ng/mL; AUC(0-∞) , 225 000 versus 234 000 ng·h/mL; AUC(0-last) , 222 000 versus 231 000 ng·h/mL, respectively. Geometric least squares mean ratios (90%CIs) comparing eslicarbazepine exposure measures were within the 80%-125% range (Cmax , 102.63% [97.07%-108.51%]; AUC(0-∞) , 96.72% [94.36%-99.13%]; AUC0-last , 96.69% [94.24%-99.21%]). In conclusion, ESL administered orally as a crushed tablet sprinkled on applesauce, or intact were bioequivalent in healthy subjects. Eslicarbazepine bioavailability was not significantly altered by crushing, indicating that ESL tablets can be administered intact or crushed.

Abuse liability assessment of eslicarbazepine acetate in healthy male and female recreational sedative users: A Phase I randomized controlled trial.

RATIONALE: Eslicarbazepine acetate (ESL) is a once-daily oral antiepileptic drug for the treatment of partial-onset seizures. Adverse events such as dizziness and somnolence reported in clinical studies suggest that ESL has detectable central nervous system (CNS) effects in addition to its antiepileptic effects. This Phase I study evaluated the abuse liability of ESL compared with that of alprazolam (ALP) and placebo (PBO) in recreational CNS depressant users. METHODS: In this single-dose, randomized, double-blind, PBO- and active-controlled crossover study, healthy recreational CNS depressant users who could discern between ALP 2mg and PBO received single oral doses of each of the following treatments with a washout interval of ≥7days between each treatment: ESL (800mg, 1600mg, 2000mg, and 2400mg); ALP (1.5mg and 3.0mg); and PBO. Subjective measures, including visual analog scales (VASs) e.g., Drug-Liking (primary endpoint), and Addiction Research Center Inventory (ARCI) Morphine-Benzedrine Group (MBG), Pentobarbital Chlorpromazine Alcohol Group (PCAG), and Lysergic Acid Diethylamide Group scales were evaluated at multiple time points up to 24h postdose. Cognitive effects were evaluated using the Choice Reaction Time (CRT), Divided Attention (DAT) and Hopkins Verbal Learning Task-Revised tests. PRINCIPAL RESULTS: Peak scores for Drug-Liking VAS (maximum effect [Emax]) were significantly higher for both ALP doses than for PBO (p<0.0001), thereby confirming study validity. Drug-Liking VAS Emax was significantly lower for all ESL doses than both ALP doses (p<0.0001). Drug-Liking VAS Emax for ESL 800mg was similar to that for PBO (least squares [LS] mean difference: 3.6; p=0.19). At the three higher ESL doses (1600mg and the supratherapeutic doses of 2000mg and 2400mg), Drug-Liking VAS Emax was significantly higher than for PBO, although the differences were minimal (LS mean difference: 9.3-13.3 out of 100). For most secondary subjective endpoints (i.e., Good Effects VAS and High VAS, ARCI-MBG, Take Drug Again VAS, Overall Drug-Liking VAS, and ARCI-PCAG; p<0.05), the effect of ESL (all doses) was significantly less than that of ALP (both doses). On most secondary measures, the dose-response relationship was relatively flat or showed saturation at higher ESL doses. Although significant differences were observed for ESL compared with those for PBO for some specific CRT and DAT endpoints (i.e., reaction time, manual tracking, hit latency), ALP demonstrated significant and dose-dependent impairment on the majority of cognitive endpoints when compared with PBO and ESL. Mean plasma concentrations of the active metabolite of ESL, eslicarbazepine, increased with increasing ESL dose. Pharmacokinetic parameters estimated for eslicarbazepine were generally comparable with results from previous studies in healthy volunteers. CONCLUSION: This study demonstrated that single doses of ESL may have less abuse liability than ALP in recreational sedative users. Although ESL had detectable subjective effects and showed some drug-'liking' at higher doses, the magnitude of these effects was small.

A first-in-human phase I study of the oral Notch inhibitor, LY900009, in patients with advanced cancer.

BACKGROUND: Notch signalling regulates stem cell development and survival and is deregulated in multiple malignancies. LY900009 is a small molecule inhibitor of Notch signalling via selective inhibition of the γ-secretase protein. We report the first-in-human phase I trial of LY900009. METHODS: Dose escalation (Part A) was performed in cohorts of three advanced cancer patients using a modified continual reassessment method and dose confirmation (Part B) was performed in ovarian cancer patients. LY900009 was taken orally thrice weekly (every Monday, Wednesday, and Friday) during a 28-d cycle. The primary objective determined the maximum tolerated dose (MTD); secondary end-points included toxicity, pharmacokinetics, pharmacodynamics, and antitumour activity. RESULTS: Thirty-five patients received LY900009 at dose levels ranging from 2-60 mg. Study drug-related adverse events were diarrhoea (46%), vomiting (34%), anorexia (31%), nausea (31%), and fatigue (23%). At 30 mg, a dose-limiting toxicity (grade III mucosal inflammation) was observed. LY900009 absorption was rapid, with median tmax at 1-4 h post-dose. LY900009 inhibited plasma levels of amyloid-ß peptide in a dose-dependent manner with 80-90% inhibition observed in the 30- to 60-mg cohorts. No responses were seen, but five patients had stable disease. Two patients (5.7%) with leiomyosarcoma and ovarian cancer received four cycles of therapy. One patient (15 mg) showed markedly increased glandular mucin consistent with pharmacologic inhibition of the Notch pathway. CONCLUSIONS: The recommended MTD schedule for future studies was 30 mg thrice weekly, which exceeds the target inhibition level observed in preclinical models to promote tumour regression in humans.

Formulation of cyclodextrin inclusion complex-based orally disintegrating tablet of eslicarbazepine acetate for improved oral bioavailability.

The present investigation was aimed towards developing a beta-cyclodextrin (ß-CD) solid dispersion (SD) based orally disintegrating tablet (ODT) of eslicarbazepine acetate (ESL), for improving the dissolution and providing fast onset of anti-epileptic action. Optimum ratio of ESL and ß-CD was determined by Job's plot. Thereafter, solid dispersions were prepared by solvent evaporation method and evaluated for yield, assay, Differential scanning calorimetry (DSC), Fourier transform infra red spectroscopy (FTIR), X-ray diffraction (XRD), and in vitro dissolution. Optimized SD was compressed into ODT by direct compression using super disintegrants and evaluated for wetting time, drug content, in vitro drug release and in vivo studies. The results of DSC, FTIR and XRD analysis supported the formation of inclusion complex. An improved dissolution with 99.95 ± 2.80% drug release in 60 min was observed in comparison to 24.85 ± 2.96% release from a plain drug suspension. Tablets with crosspovidone as a super disintegrant showed the least disintegration time of 24.66 ± 1.52 s and higher in vitro drug release against marketed tablets. In vivo studies indicated that the formulated tablets had 2 times higher bioavailability than marketed tablets. Thus, the developed ß-CD-ESL SD-ODT could provide faster onset of action and higher bioavailability, which would be beneficial in case of epileptic seizures.

Pharmacokinetic/pharmacodynamic evaluation of eslicarbazepine for the treatment of epilepsy.

INTRODUCTION: Eslicarbazepine acetate (ESL) is a novel antiepileptic drug registered as the adjunctive treatment of partial-onset seizures in adults. As a third-generation medication, ESL is believed to have favorable efficacy/safety profile and pharmacokinetic properties in comparison with related drugs (carbamazepine and oxcarbazepine). AREAS COVERED: The aim of the paper was to evaluate pharmacodynamic and pharmacokinetic properties of ESL with aspect to epilepsy treatment. The review of the scientific literature was based on the PubMed database, Clinical Trials, FDA and European Medicines Agency websites to elicit current information on drug metabolism, mechanism of action and efficacy/safety profile. EXPERT OPINION: Results of clinical trials indicate that ESL possessed a favorable profile of anticonvulsant efficacy and tolerability as an add-on therapy in adult patients at daily doses of 800 and 1200 mg. Pediatric trials are in progress and their results will allow to characterize a role of ESL in the treatment of epilepsy in children.

Targeting pharmacoresistant epilepsy and epileptogenesis with a dual-purpose antiepileptic drug.

In human epilepsy, pharmacoresistance to antiepileptic drug therapy is a major problem affecting a substantial fraction of patients. Many of the currently available antiepileptic drugs target voltage-gated sodium channels, leading to a rate-dependent suppression of neuronal discharge. A loss of use-dependent block has emerged as a potential cellular mechanism of pharmacoresistance for anticonvulsants acting on voltage-gated sodium channels. There is a need both for compounds that overcome this resistance mechanism and for novel drugs that inhibit the process of epileptogenesis. We show that eslicarbazepine acetate, a once-daily antiepileptic drug, may constitute a candidate compound that addresses both issues. Eslicarbazepine acetate is converted extensively to eslicarbazepine after oral administration. We have first tested using patch-clamp recording in human and rat hippocampal slices if eslicarbazepine, the major active metabolite of eslicarbazepine acetate, shows maintained activity in chronically epileptic tissue. We show that eslicarbazepine exhibits maintained use-dependent blocking effects both in human and experimental epilepsy with significant add-on effects to carbamazepine in human epilepsy. Second, we show that eslicarbazepine acetate also inhibits Cav3.2 T-type Ca(2+) channels, which have been shown to be key mediators of epileptogenesis. We then examined if transitory administration of eslicarbazepine acetate (once daily for 6 weeks, 150 mg/kg or 300 mg/kg) after induction of epilepsy in mice has an effect on the development of chronic seizures and neuropathological correlates of chronic epilepsy. We found that eslicarbazepine acetate exhibits strong antiepileptogenic effects in experimental epilepsy. EEG monitoring showed that transitory eslicarbazepine acetate treatment resulted in a significant decrease in seizure activity at the chronic state, 8 weeks after the end of treatment. Moreover, eslicarbazepine acetate treatment resulted in a significant decrease in mossy fibre sprouting into the inner molecular layer of pilocarpine-injected mice, as detected by Timm staining. In addition, epileptic animals treated with 150 mg/kg, but not those that received 300 mg/kg eslicarbazepine acetate showed an attenuated neuronal loss. These results indicate that eslicarbazepine potentially overcomes a cellular resistance mechanism to conventional antiepileptic drugs and at the same time constitutes a potent antiepileptogenic agent.