Abstract
The rhizome of Kaempferia galanga (Zingiberaceae) is extensively used in traditional medicine by utilizing its various biological activities. It has been proven that ethyl-para-methoxycinnamate (EPMC) and other polyphenolic compounds are present in considerable amounts in the ethanolic extract of K. galanga rhizome (EKG). Our previous study confirmed that a dose of 0.5-1% of EKG demonstrated anti-inflammatory activity and a wound-healing effect in chemical-induced oral mucosal ulcers of Wistar rats. Currently, there are no reports on the formulation of oral gel containing EKG, thus revealing the potential of EKG to be developed as a herbal oral gel for mucosal ulcers. This study aims to formulate the best mucoadhesive oral care gel containing EKG in terms of physical stability. The presence of EPMC and the total phenols in the best EKG gel were also determined. The results revealed that Carbopol 934 is the best gelling agent for EKG gel preparations as proven by its stability during 14 days of storage. The statistical analysis resulted in a significant difference between the physical stability of the Carbopol 934-based EKG gel preparation compared to three commercial oral care gel products (p < 0.05). RP-HPLC chromatograms indicated that EPMC was identified in Carbopol 934-based gels containing 5% and 10% EKG at 6.056 and 6.146 min, respectively, with polyphenol levels of 1201.2557 mg/kg and 1849.1506 mg/kg, respectively. The hedonic test performed on 30 respondents to measure the degree of consumer acceptance and satisfaction confirmed that 5% EKG gel is the most sensorially accepted by the respondents. Data were analyzed using paired t-tests, one-way ANOVA, and a Kruskal-Wallis test. Taken together, the Carbopol 934-based gel containing 5% EKG could potentially be further developed as a topical anti-oral mucosal ulcer drug for clinical purposes.