Optimized Microencapsulation of Zingiber zerumbet Extract: Enhancing Zerumbone Solubility

The Zingiber zerumbet (L.) Sm., Zingiberaceae (popularly known as bitter ginger), is a plant with notable therapeutic potential due to its bioactive compounds. The sesquiterpene zerumbone is the main compound that can be observed in this species, and may be adopted as a marker but this compound exhibits low aqueous solubility limiting its pharmaceutical application. Microencapsulation is a tool that can be applied to deal with this solubility limitation; therefore, this study aimed to produce a microencapsulated dry extract guided by the best condition in the spray dryer to improve the zerumbone concentration and solubility. Two experimental designs (full factorial 3 2 ) were implemented to optimize the excipient (hydroxypropyl-β-cyclodextrin—HPBCD; and polyvinylpyrrolidone K-30—PVP) and drying parameters, evaluating yield and zerumbone retention. The HPBCD formulations showed higher zerumbone retention (up to 58%) and yield in both experimental designs. The optimized extracts improved the zerumbone solubility (up to 80%). Chromatographic analyses (UHPLC-MS/MS and GC-MS) confirmed the preservation of key chemical constituents after drying. Particle analysis demonstrated spherical, hollow microparticles with surface features affecting solubility and stability. These results underscore the critical role of excipient selection and process conditions in producing dry extracts with enhanced physicochemical properties, facilitating the development of stable, versatile pharmaceutical forms from Z. zerumbet extracts.