Pharmacokinetics and Safety of Single-Dose Wafermine™ (Ketamine Sublingual Wafer) in Healthy Subjects

This is a Phase 1, open-label, three-period crossover study evaluating the pharmacokinetics and safety of single-dose Wafermine™ (ketamine sublingual wafer) at dose levels of 25 mg, 50 mg, and 75 mg in healthy adult participants under fasting conditions. Participants will receive all three dose levels in a fixed ascending sequence during a single inpatient admission, with washout periods between doses. Pharmacokinetic sampling will be conducted over 36 hours following each dose.

Inclusion Criteria 1. Clinically healthy participants (male and female) aged ≥ 18 to ≤ 65 years at the time of signing the informed consent. 2. Research participants with no history of clinically significant cardiac, endocrine, gastrointestinal, hematological, hepatic, immunological, metabolic, urological, pulmonary, neurological, dermatological, or renal diseases or comorbidity of significance at the discretion of the Principal Investigator (or his/her delegate). The following medical history are permitted at the discretion of the Principal Investigator: history of childhood asthma; prior history of cholecystectomy; history of eczema with no use of steroid creams for 3 months prior to screening; history of fully resolved gestational diabetes; current or history of ADHD, anxiety or antidepression ( stable condition with no use of antidepressants 6 months prior to screening) 3. Be able and willing to read, understand, sign, and date the Informed Consent Form prior to entering the study. 4. Have adequate venous access for blood sampling. 5. Female participants are eligible only if all the following contraceptive requirements are met: These requirements also apply to ova donation. * Women of non-childbearing potential (WONCBP) are not required to use contraception and are defined as women who meet at least one of the following criteria: * Have undergone surgical sterilisation (e.g., hysterectomy, bilateral salpingectomy, or bilateral oophorectomy), or * Are postmenopausal, defined as at least 12 consecutive months of amenorrhea without an alternative medical cause, with confirmation by follicle-stimulating hormone (FSH) levels at screening, where required. * Women of childbearing potential (WOCBP) must agree to use highly effective methods of contraception, defined as methods with a failure rate of \6 months before screening) may be included at the discretion of the Investigator or delegate). Risk of infection 7. Positive serology for hepatitis C virus (HCV), hepatitis B virus (HBV) or human immunodeficiency virus (HIV). 8. Presence of chronic, recurrent, or severe infection (e.g., pneumonia, sepsis) at the discretion of the Principal Investigator, within 90 days prior to the screening visit and between the screening visit and Day -1. 9. Presence of symptoms of bacterial, fungal, or viral infection (including upper respiratory tract infection) within 14 days prior to the screening visit and between screening and Day -1. Participants with local fungal infection (e.g., candidiasis, ringworm, tinea pedis) are eligible for reevaluation after successful treatment of the infection. 10. History of clinically significant condition involving the bladder or urinary tract, including frequent urinary tract infections (e.g. \> 2 per year), or current symptoms of bladder irritation such as frequent or urgent need to urinate or burning with urination. 11. Any immunization or vaccine administered within 30 days prior to Day 1. Laboratory assessment and results 12. Abnormal and clinically significant results at the discretion of the Principal investigator (or his/her delegate) in the laboratory tests and electrocardiogram of the screening visit. Laboratory values out of range and determined to be not clinically significant at the discretion of the Principal Investigator or his/her delegate may be repeated on one occasion, the subject may be enrolled if the repeated value is within the normal range. 13. Participants with aspartate aminotransferase (AST), alanine aminotransferase (ALT), or total bilirubin values ≥1.5 × upper limit of normal (ULN) at screening. Pre-medicated and concomitant medications 14. Participation in any other investigational study with drugs, biologics, medical devices, or treatment with an investigational product or therapy approved for investigational use within the 30 days prior to or 5 half-lives, whichever is greater, by Day -1. 15. Use of any Over-The-Counter (OTC)/non-prescribed drugs including vitamins, minerals, supplements or herbal medicines within 1 week of Period 1 study drug administration, or intake of prescribed drugs within 2 weeks of Period 1 study drug administration (or longer if the medication has a half-life long enough to potentially expose the healthy participant to any significant systemic exposure). \[Exception: hormone replacement therapy and oral contraceptives in female participants is allowed.\] 16. Use of drugs with enzyme-inducing properties (such as rifampicin and St John's Wort) or any drug known to be either a moderate or strong inhibitor of CYP3A4 or CYP2B6 within 3 weeks or 5 half-lives, whichever is greater, prior to treatment period 1 and throughout the study. Others 17. History of abuse or dependence on alcohol or illegal/recreational drugs during the development of the study. 18. Positive results on the urine drug screen or breath alcohol test at screening and/or pre-dose. \[Exception: a positive result on the urinary drug screen at screening only is allowed at the discretion of the Investigator provided the result can be reliably explained by recent medication and/or dietary history.\] 19. Current or recent use of tobacco or nicotine-containing products, defined as: * Any smoking or nicotine use (cigarettes, e-cigarettes, vaping, chewing tobacco, etc.) within 30 days prior to screening, or * History of regular (daily) smoking, or * Casual/social smoking (\>5 cigarettes or equivalent per week on average in the past 6-12 months) * Participants with history of occasional smoking (≤5 cigarettes/week) may be considered if they can commit to full abstinence during the entire study period including from screening through inpatient stays, and pass all other eligibility criteria (at the discretion of the Principal Investigator). 20. Alcohol consumption 24 hours prior to Day -1. 21. Habitual alcohol consumption \> 14 units per week for men and \> 10 units per week for women. One unit is equivalent to 250 mL of beer, 25 mL of hard liquor, or 125 mL of wine. 22. Intake of beverages containing xanthines (coffee, tea, chocolate, cocoa, , cola) or charcoal-roasted foods 24 hours prior to Day -1. 23. Habitual consumption of more than 4 caffeinated beverages in a period of 24 hours. 24. Blood donation of one unit (approximately 450-500 mL) within the last 30 days prior to screening will be exclusionary. 25. Strenuous physical exercise (e.g., heavy lifting, weight training, calisthenics, and aerobic exercise) within 48 hours prior to Day-1. Walking at a normal pace is allowed. 26. Unwillingness or inability to comply with the requirements of the protocol. 27. Other unspecified reasons that, at the discretion of the Principal Investigator or the Sponsor, determine that the subject is not suitable for inclusion. 28. Participants who had been hospitalized in the 6 months prior to the screening visit.