Liquid vs. pill: new study tests easier way to take seizure drug

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria * Aged between 18 and 50 years (inclusive). * Considered healthy after a comprehensive clinical assessment (medical history + complete physical exam). * Body Mass Index (BMI) between 18 and 30 kg/m² (inclusive) and body weight ≥ 50 kg at screening. * Normal blood pressure (BP) and heart rate (HR) after 10 minutes supine at screening : Systolic BP: 90-145 mmHg, Diastolic BP: 45-90 mmHg, HR: 40-90 bpm, Or values outside these ranges but judged not clinically significant (NCS) by the Investigator. * Normal ECG at screening (10-min resting 12-lead ECG): PR interval: 110-210 ms, QRS interval : \< 120 ms, QTcF interval: ≤ 450 ms, No evidence of sinus node dysfunction, Or values outside these ranges but judged NCS by the Investigator. * Laboratory parameters within normal ranges (hematology, biochemistry, urinalysis); slight deviations allowed if not clinically relevant per Investigator. * Women of non-childbearing potential, or women of childbearing potential using at least one acceptable contraceptive method throughout the study and 1 month after last treatment. * Female subjects of childbearing potential: negative pregnancy test (serum or urine) at screening and Day 0. * Covered by Health Insurance System and/or compliant with National Law requirements for biomedical research. * Able and willing to comply with study requirements. * Written informed consent obtained. Exclusion Criteria * Unsuitable veins for repeated venipuncture. * Relevant history/presence of cardiovascular, pulmonary, gastrointestinal, hepatic, renal, metabolic, hematological, neurological, psychiatric, systemic, or infectious disease. * Evidence of any clinically significant acute or chronic disease. * History of suicidal ideation or suicide attempt. * Surgery (including clinical trial procedures) within 2 months before dosing. * Blood donation within 2 months before dosing. * History/presence of drug hypersensitivity, asthma, or allergy. * Known hypersensitivity to study materials or related compounds. * Inability/difficulty swallowing capsules. * No possibility of emergency contact. * Any drug intake (except paracetamol) within 4 weeks prior to dosing or \< 5 half-lives (whichever longer). Prohibited: carbamazepine, phenytoin, phenobarbital, CYP enzyme modulators. * Use of herbal products affecting CYP enzymes within 2 weeks or \< 5 half-lives before dosing. * Special diets (vegetarian, vegan, gluten-free). * Vigorous exercise from 4 days before dosing until post-study assessments. * Pregnant or breastfeeding women. * Drug/alcohol abuse history, daily alcohol intake \> 4 drinks, or positive alcohol test. * Excessive xanthine beverages (\> 5 cups/day). * Nicotine use \> 5 cigarettes/day or inability to abstain 48h before and during study. * Intake of grapefruit/Seville oranges/poppy seed or other CYP modulators 1 week before dosing and during study. * Intake of methylxanthines (coffee, tea, cola, cocoa, mate, guarana, chocolate) or quinine (e.g., tonic water) from 48h before dosing and during study. * Unable/unwilling to follow diet requirements (see protocol section 10.7). * Positive test for HBsAg, HCV antibody, or HIV 1/2. * Positive drug screen. * Significant biological or clinical abnormalities judged incompatible with study. * Participation in another interventional trial during exclusion period or investigational product within last 60 days or \< 5 half-lives. * Under guardianship, curatorship, or deprived of liberty. * Under Court protection. * Would exceed €6000 compensation for biomedical research in last 12 months (including this study). * Health status not allowing provision of informed consent.