Bioequivalence of eslicarbazepine acetate from two different sources of its active product ingredient in healthy subjects

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.

Modeling and simulations to support dose selection for eslicarbazepine acetate therapy in pediatric patients with partial-onset seizures

Modeling and simulations were used to support body weight-based dose selection for eslicarbazepine acetate (ESL) in pediatric subjects aged 4–17 years with partial-onset seizures. A one-compartment pediatric population pharmacokinetic model with formulation-specific first-order absorption, first-order elimination, and weight-based allometric scaling of clearance and distribution volume was developed with PK data from subjects 2–18 years of age treated with ESL 5–30 mg/kg/day. Covariate analysis was performed to quantify the effects of key demographic and clinical covariates (including body weight and concomitant use of carbamazepine, levetiracetam, and phenobarbital-like antiepileptic drugs [AEDs]) on variability in PK parameters. Model evaluation performed using a simulation-based visual predictive check and a non-parametric bootstrap procedure indicated no substantial bias in the overall model and in the accuracy of estimates. The model estimated that concomitant use of carbamazepine or phenobarbital-like AEDs with ESL would decrease the exposure of eslicarbazepine, and that concomitant use of levetiracetam with ESL would increase the exposure of eslicarbazepine, although the small effect of levetiracetam may not represent a true difference. Model-based simulations were subsequently performed to apply target exposure matching of selected ESL doses for pediatric subjects (aged 4–17 years) to attain eslicarbazepine exposures associated with effective and well-tolerated ESL doses in adults. Overall, model-based exposure matching allowed for extrapolation of efficacy to support pediatric dose selection as part of the submission to obtain FDA approval for ESL (adjunctive therapy and monotherapy) in subjects aged 4–17 years, without requiring an additional clinical study.