An antiepileptic medication is eslicarbazepine acetate. It is a prodrug that is converted to eslicarbazepine, also known as S-licarbazepine, an active oxcarbazepine metabolite. ..As such, its mode of action is the same as that of oxcarbazepine. Theoretically, oxcarbazepine may result in higher peak levels of (S)-(+)-licarbazepine immediately following dosage than eslicarbazepine acetate, which could enhance tolerability[1].

Absorption, Distribution and Excretion
Eslicarbazepine's active metabolites have high bioavailability, reaching peak serum concentrations 1–4 hours after administration. Food does not affect the absorption of eslicarbazepine acetate. Eslicarbazepine acetate and its metabolites are primarily excreted via the kidneys. Approximately two-thirds of the active metabolites are excreted unchanged, and one-third are excreted as glucuronide conjugates. This accounts for approximately 90% of total excreted metabolites, with the remaining 10% being minor metabolites. Renal tubular reabsorption of eslicarbazepine is expected. Based on population pharmacokinetic analysis, the apparent volume of distribution of eslicarbazepine in a 70 kg body weight is 61.3 L. In healthy subjects with normal renal function, the renal clearance of eslicarbazepine is approximately 20 mL/min.

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Metabolism/Metabolites
Eslicarbazepine acetate is rapidly and extensively metabolized via first-pass hydrolysis to its major active metabolite, eslicarbazepine. Eslicarbazepine accounts for approximately 92% of systemic exposure. Minor active metabolites (R) – liscarbazepine and oxcarbazepine – account for <5% of systemic exposure. The active metabolite is subsequently metabolized to inactive glucuronide, accounting for approximately 3% of systemic exposure. In human liver microsomal studies, eslicarbazepine exhibits moderate inhibition of CYP2C19 and slight activation of UGT1A1-mediated glucuronidation. Studies have shown that eslicarbazepine can induce the expression of the CYP3A4 enzyme in vivo.

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Biological Half-Life
The apparent plasma half-life of eslicarbazepine is 10–20 hours in healthy subjects and 13–20 hours in patients with epilepsy. Steady-state plasma concentrations are reached after 4–5 days of once-daily administration.

Protein Binding
Eslicarbazepine exhibits relatively low binding to plasma proteins, below 40%, and this binding is concentration-independent. In vitro studies have shown that the presence of other drugs (such as warfarin, diazepam, digoxin, phenytoin sodium, or tolbutamide) has no significant effect on plasma protein binding. Similarly, the binding rates of these drugs are not significantly affected by eslicarbazepine.

[1]. Aptiom (Eslicarbazepine Acetate) as a Dual Inhibitor of β-Secretase and Voltage-Gated Sodium Channel: Advancement in Alzheimer's Disease-Epilepsy Linkage via an Enzoinformatics Study. CNS & Neurological Disorders Drug Targets Volume 13 , Issue 7 , 2014.

Eslicarbazepine acetate is the acetate ester of riscarbazepine, with the S configuration. It is an anticonvulsant approved in Europe and the United States for adjunctive treatment of epilepsy. It has both anticonvulsant effects and is also a drug allergen. It is an acetate, dibenzodiazepine, carboxamide compound belonging to the urea class. Its function is related to riscarbazepine. Eslicarbazepine acetate (ESL) is an anticonvulsant approved in Europe, the United States, and Canada for adjunctive treatment of partial-onset epilepsy that is not effectively controlled by conventional therapy. Eslicarbazepine acetate is a prodrug that is rapidly converted in vivo to its major active metabolite, eslicarbazepine. The mechanism of action of eslicarbazepine is not fully understood, but it is known to exert its anticonvulsant effect by inhibiting repetitive neuronal firing and stabilizing the inactive state of voltage-gated sodium channels, thereby preventing sodium channels from reverting to an activated state that could trigger seizures. Eslicarbazepine acetate is marketed in North America under the brand name Aptiom, and in Europe under the brand names Zebinix or Exalief. It is available in tablet strengths of 200 mg, 400 mg, 600 mg, and 800 mg, taken once daily, either before or after meals. Side effects of eslicarbazepine acetate include dizziness, drowsiness, nausea, vomiting, diarrhea, headache, aphasia, poor concentration, psychomotor retardation, speech disorders, ataxia, depression, and hyponatremia. Suicidal ideation monitoring is recommended for patients taking eslicarbazepine acetate.
See also: Eslicarbazepine (with active ingredient).
Drug Indications
Eslicarbazepine acetate is indicated for the treatment of partial-onset seizures in patients aged 4 years and older.
FDA Label
Zebinix is indicated for the adjunctive treatment of partial-onset seizures (with or without secondary generalized seizures) in adults, adolescents, and children aged 6 years and older.
Exalief is indicated for adjunctive treatment of partial-onset epilepsy in adults (with or without secondary generalized seizures).
Treatment of Partial-Onset Epilepsy
Mechanism of Action

Eslicarbazepine acetate is converted into the active metabolite eslicarbazepine, which exerts its anticonvulsant effect. Its exact mechanism of action is unclear, but it is presumed to be related to the inhibition of voltage-gated sodium channels. In vitro electrophysiological studies have shown that eslicarbazepine can inhibit recurrent neuronal firing by stabilizing the inactivated state of voltage-gated sodium channels and preventing their reactivation. In vitro studies have also shown that eslicarbazepine can inhibit T-type calcium channels, which may also be related to its anticonvulsant activity.
Pharmacodynamics

Eslicarbazepine acetate can cause a dose- and concentration-dependent increase in heart rate and a prolongation of the PR interval.

C17H16N2O3

296.3205

296.116

236395-14-5

179344

White to off-white solid powder

1.3±0.1 g/cm3

427.4±55.0 °C at 760 mmHg

183-185ºC

212.3±31.5 °C

0.0±1.0 mmHg at 25°C

1.655

1.7

1

3

2

22

440

1

CC(=O)O[C@H]1CC2=CC=CC=C2N(C3=CC=CC=C13)C(=O)N

QIALRBLEEWJACW-INIZCTEOSA-N

InChI=1S/C17H16N2O3/c1-11(20)22-16-10-12-6-2-4-8-14(12)19(17(18)21)15-9-5-3-7-13(15)16/h2-9,16H,10H2,1H3,(H2,18,21)/t16-/m0/s1

[(5S)-11-carbamoyl-5,6-dihydrobenzo[b][1]benzazepin-5-yl] acetate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: (1). This product requires protection from light (avoid light exposure) during transportation and storage.  (2). Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ≥ 100 mg/mL (~337.47 mM)

Solubility in Formulation 1: ≥ 10 mg/mL (33.75 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 100.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 10 mg/mL (33.75 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 100.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 10 mg/mL (33.75 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 100.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)