A Study of Phenytoin Mucoadhesive Film for Oral Ulcers in Healthy Volunteers

The goal of this clinical trial is to learn if a new 1% Phenytoin mucoadhesive film is safe and works to treat oral ulcers in healthy adult volunteers and patients with oral ulcers. The main questions it aims to answer are the following: Is the 1% Phenytoin film safe and well-tolerated when placed on oral ulcers? Does the film reduce pain and improve ulcer healing compared to a blank film? Researchers will compare participants receiving the 1% Phenytoin mucoadhesive film to those receiving a blank (placebo) film to see if the active film improves healing and reduces pain. Participants will: Have the assigned film placed directly over their oral ulcer once daily for 7 consecutive days. Attend regular clinic visits for check-ups, including blood tests and monitoring of ulcer appearance, body weight, and food intake. Report any pain, discomfort, or changes in their condition to the research team.

Inclusion Criteria: 1. Male or female adults aged 18 to 50 years. 2. General good health, confirmed by medical history, physical examination, vital signs, and clinical laboratory tests (hematology, biochemistry, urinalysis). 3. Body Mass Index (BMI) between 18.5 and 30 kg/m². 4. For patients with existing ulcers: Clinical diagnosis of at least one oral ulcer (e.g., recurrent aphthous stomatitis) with a diameter between 3 mm and 10 mm at baseline. 5. For healthy volunteers: no current oral lesions. 6. Ability to understand and provide written informed consent. 7. Willingness to comply with all study procedures, including daily clinic visits and application of the film for 7 consecutive days. 8. Women of childbearing potential must have a negative pregnancy test at screening and agree to use highly effective contraception during the study. Exclusion Criteria: 1. Known hypersensitivity or allergy to phenytoin, other hydantoins, or any excipients in the mucoadhesive film. 2. Clinically significant cardiovascular, hepatic, renal, gastrointestinal, hematologic, or psychiatric disease. 3. Presence of severe oral pathology, oral candidiasis, or active oral infection (e.g., herpes simplex) that could confound ulcer assessments. 4. Use of any systemic or topical medication for oral ulcers (e.g., corticosteroids, anesthetics) within 7 days prior to enrollment. 5. Use of drugs known to interact with phenytoin (e.g., warfarin, folic acid, certain antibiotics, and antifungals) within 30 days prior to enrollment. 6. History of heavy smoking (more than 10 cigarettes/day) or alcohol abuse, as these impair wound healing. 7. Pregnant or breastfeeding women. 8. Participation in another investigational drug or device study within 30 days prior to screening. 9. Immunocompromised status (e.g., HIV positive, chronic hepatitis, or current immunosuppressive therapy). 10. Any condition that, in the opinion of the Investigator, would compromise the safety of the participant or the quality of the study data.