Dual-Loaded Galangal Extract and Lemongrass Oil Biobased Self-Emulsifying System for Denture-Cleansing Applications

Denture stomatitis, an inflammation involving the formation of plaque material on the denture surfaces, presents a great deal of difficulty for denture wearers. Although denture cleansers are widely used to prevent this condition, commercial formulations containing inorganic ingredients can cause adverse health effects, promote microbial proliferation, and alter denture color. To address these limitations, we developed, for the first time, a dual-loaded galangal extract (GE) and lemongrass oil (LGO) solid self-emulsifying drug delivery system (solid-SEDDS-GL) as a novel natural-based denture cleanser powder. Gas chromatography–mass spectrometry (GC–MS) analysis revealed that the major bioactive compounds in GE and LGO were 1′-acetoxychavicol acetate (ACA) and citral (neral and geranial), respectively. Solid-SEDDS-GL formulations were developed and characterized for their physicochemical properties, antifungal activity against Candida albicans, effects on denture resin color, and storage stability. The developed solid-SEDDS-GL exhibited properties comparable to those of commercial products, including a low moisture content (<10%), rapid emulsification time (<2 min), small, homogeneous particulate size (<100 nm), and a mildly acidic pH (∼5.0). High encapsulation efficiency (>80%) was achieved for both ACA from GE and citral from LGO, as determined by HPLC. The formulation demonstrated antifungal activity against C. albicans, with minimum inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values at a 1:8 dilution, achieving complete fungal eradication within 60 min. Additionally, the formulation reduced fungal adhesion on simulated denture acrylic resin by over 90%, while preserving denture color integrity. The product remained stable for at least 6 months under ambient and 4 °C storage conditions. In conclusion, the solid-SEDDS-GL-based denture cleanser powder shows potential as a plant-based alternative for preventing denture stomatitis.