Several natural products have been use to promote wound healing and relieve pain. Acmella oleracea has a component that has anesthetic and anti-inflammatory properties.

The mucoadhesive film can be improved by drug delivery system due to close contact with the absorption tissue leading to improvement in both local and systemic effects.

This study aims to evaluate the effectiveness and safety of mucoadhesive film containing Acmella oleracea extract in healthy subjects. This is a randomised, double-blind (participant and investigator), parallel-controlled clinical trial. In total, approximately 72 subjects will be enrolled into study.

Objectives

1. To investigate the potential of skin allergy reaction to mucoadhesive film containing Acmella oleracea extract in healthy subjects
2. To study the duration of mucosal adhesion of mucoadhesive film
3. To study the local anesthetic effect, participant's satisfaction and adverse effect of mucoadhesive film containing Acmella oleracea extract

Total 72 Participants will divided into 2 groups by dentist who was not an examiner performed the randomization using blocked randomization (block of 4) from program of https://www.sealedenvelope.com/simple-randomiser/v1/lists/1. Study group will receive mucoadhesive film containing Acmella oleracea extract while control group will receive mucoadhesive film without active component. All participants in the study group will be test for allergic reaction of mucoadhesive film by skin prick test and patch skin test before testing and have to follow-up appointments (at 2, 4 and 7 days after skin test). At first visit, all participants will received oral examination and informed how to use mucoadhesive film by examiner. Then participants will asked to apply the mucoadhesive film at oral mucosa of lower lip. The effectiveness of intra-oral mucoadhesive film in this study will evaluated as follows :

1. Duration of mucosal adhesion and adverse effect by self report
2. The local anesthetic effect by using Numeric rating scale (NRS)
3. Participant's satisfaction by using Numeric rating scale (NRS)

The statistical methods :

General and oral health data, duration of mucosal adhesion will reported as frequencies, percentages and means (Standard deviation). The different of NRS score between groups will analyzed Independent t- test or Mann-Whitney U test. Using SPSS software. Statistically significant will considered at p-value < 0.05.

Inclusion Criteria:

1. Healthy people age 18-60 years old and do not have regular medication.
2. Able to give the consent formation in a study and to cooperate in answering questionnaires or data records in google formation.
3. The participants must not have any wounds, tattoos, inflammation or pathology on the oral mucosa and skin of testing area.
4. The participants who can come to follow up for a specified period of time.

Exclusion Criteria:

1. The participants who need dental treatment or necessary to use topical medication to treat oral diseases during the study period (7 days).
2. History of allergic to the components of mucoadhesive film and/or have a history of other allergies.
3. The vulnerable participants include pregnancy or lactating women and disabilities.
4. History of using antihistamines drugs during the one-week period prior to joining the study or participants who need to use such antihistamines during the time participating in the study.
5. History of using topical gluco-corticosteroids during the one-week period on skin testing areas.