Safety of Transmucosal Capsaicin Sphenopalatine Ganglion Stimulation in Acute Ischemic Stroke

Safety of Transmucosal Capsaicin for Chemical Sphenopalatine Ganglion Stimulation in Acute Ischemic Stroke Within 24 Hours of Symptom Onset: A Randomized Double-Blind Placebo-Controlled Trial

This study will evaluate the safety and tolerability of a dissolvable oral film containing a very small dose of capsaicin (the compound that produces the "hot" sensation in chili peppers) in adults with acute ischemic stroke. The film is designed to stimulate nerves in the mouth that may activate the sphenopalatine ganglion, a structure involved in regulating blood flow to the brain. The main purpose of this study is to determine whether the capsaicin film can be given safely to patients with acute ischemic stroke when started within 24 hours of symptom onset.

Participants will be randomly assigned (like flipping a coin) to receive either the capsaicin oral film or a placebo film that looks and tastes similar but contains no capsaicin. Neither the participants nor the clinical team will know which film is given (double-blind). All participants will continue to receive standard medical care for acute ischemic stroke.

After administration of the study film, participants will be closely monitored for side effects and changes in vital signs (blood pressure, heart rate, respiratory rate, temperature, and oxygen saturation) at prespecified time points up to 72 hours. The primary outcome is the frequency of adverse events related to the study product within 72 hours after treatment begins. Participants will also be followed clinically up to 3 months as part of usual stroke care.

The results of this study will help determine whether this approach is safe and feasible, and whether further studies are warranted.

Inclusion Criteria:

• Age between 18 and 80 years.
• National Institutes of Health Stroke Scale (NIHSS) score between 6 and 20 at screening.
• Symptom onset within 24 hours prior to study intervention.
• Pre-stroke modified Rankin Scale (mRS) score ≤1.
• Provision of written informed consent by the participant or legally authorized representative.

Exclusion Criteria:

• Intracranial hemorrhage on neuroimaging.
• Severe impairment of consciousness judged by the investigator to preclude safe participation.
• Persistent blood pressure >220/120 mmHg after initial medical management.
• Severe systemic disease that, in the investigator's judgment, may interfere with study participation or safety.