Development of Liquid Crystal Containing Encapsulated Aromatic Extracts from Hedychium coronarium J. Koenig for Cosmetic Applications

Abstract

Hydechium coronarium J. Koenig flowers are used in the perfume industry, and the other parts of the plants have been disposed of every year. Therefore, this study aimed to investigate the potential of aromatic extracts from H. coronarium rhizomes, leaves, and leaf sheaths for use as cosmeceutical active ingredients and develop the encapsulation and lamella liquid crystal (LLC) systems. The aromatic compounds from H. coronarium rhizomes, leaves, and leaf sheaths were extracted in the forms of concrete, absolute, and essential oils. Their chemical compositions of each extract were investigated by gas chromatography–mass spectrometry (GC–MS). Each aromatic extract was investigated for their biological activities related to cosmetic and cosmeceutical applications, including antioxidant, anti-aging, and anti-tyrosinase activities. The irritation tests were used to evaluate the safety of each aromatic extracts. The encapsulation systems were developed to reducing the irritation properties of aromatic extracts from H. coronarium. Various factors affecting the encapsulation systems were investigated, including types of wall material and the amount of H. coronarium rhizome oil. Each encapsulation system was evaluated for physical appearance, solubility, hygroscopicity, entrapment efficiency, morphology, stability, and irritation properties. In addition, lamella liquid crystal (LLC) systems were developed for further applications in cosmetics and cosmeceuticals. Various factors affecting the LLCs were investigated, including types and amounts of the oil phase. Each LLCs were identified using a polarized light microscope and characterized for their physical appearance, viscosity, pH, stability, and irritation properties. Among various H. coronarium aromatic extracts, absolute from H. coronarium rhizome exhibited the most potential in antioxidant and anti-collagenase activities. On the other hand, the essential oil from H. coronarium rhizome demonstrated potent anti-tyrosinase activity with an IC50 value of 1.8 ± 0.6 µg/mL, significantly more potent than kojic acid, whose IC50 value was 16.2 ± 3.7 µg/mL. Therefore, the rhizome essential oil was selected for the encapsulation. The encapsulated H. coronarium oil, using gum Arabic as a shell material, exhibited the most suitable characteristics with high water solubility, low hygroscopicity, low water activity, low moisture content, and high entrapment efficiency of 99.7 ± 6.7% w/w. The encapsulations were stable after the storage in 8 cycles of heating-cooling condition. Interestingly, encapsulation reduced the irritation potential of H. coronarium oil with decreasing the irritation score (IS) from 13.3 ± 1.4 to 4.1 ± 0.2. Regarding the LLC development, the formulation comprising of encapsulated H. coronarium rhizome oil, coco-caprylate, sorbitan stearate, sucrose cocoate, Carbopol U21, and DI water was the most suitable due to its appealing characteristics, good stability, and induce no irritation. Therefore, the LLC formulation containing encapsulated H. coronarium rhizome oil could be successfully developed to reduce irritation associated with the H. coronarium oil, which possessed a potential to be used as cosmeceutical active ingredients for skin whitening.