Mucoadhesive Gel Based on Cinnamomum cassia Essential Oil and Punica granatum Extract for Oral Candidiasis: A Pilot Study of Plant Synergism

Background/Objectives: Oral candidiasis is one of the most prevalent infections among denture wearers and is frequently associated with colonization by Candida albicans. In this context, natural products have been investigated as alternative therapeutic strategies, particularly Punica granatum peel extract and Cinnamomum cassia essential oil, which are recognized for their antimicrobial activity. This study aimed to develop and evaluate a mucoadhesive gel loaded with P. granatum and C. cassia for the treatment of oral candidiasis. Methods: The synergistic potential between the plant materials was assessed using the checkerboard method against C. albicans, and the inhibitory concentration was used as a parameter for the development of the mucoadhesive formulation. The gel was characterized and subsequently evaluated in denture-wearing patients with clinical manifestations of oral candidiasis for 14 days, with the results compared to treatment with nystatin. Results: The combination of plant materials exhibited a synergistic effect, with an inhibitory concentration of 0.1953 mg mL−1 for both components. Clinical evaluation demonstrated a satisfactory therapeutic response in patients treated with the gel, with resolution of symptoms at the end of the treatment period. Statistically significant advantages were also observed regarding ease of application, absence of irritation, and reduced interference with speech and swallowing. In contrast, the group treated with nystatin showed only partial clinical improvement, with additional therapy required in some cases. Conclusions: These findings indicate that the mucoadhesive gel represents a promising topical strategy for the management of oral candidiasis in denture wearers. However, studies with longer follow-up periods are required to consolidate the clinical evidence.