Green tea glycolic extract-loaded liquid crystal systems: development, characterization and microbiological control

Abstract

Liquid crystal systems (LCSs) have interesting cosmetic applications because of their ability to increase the therapeutic efficiency and solubility of active ingredients. The aim of the present research was to develop green tea glycolic extract-loaded LCSs, to characterize and to perform microbiological control. The ternary phase diagram was constructed using polysorbate 20, silicone glycol copolymer (SGC) , and distilled water with 1.5% glycolic green tea extract. The systems were characterized by polarized light microscopy. Formulations selected were characterized as transparent viscous systems and transparent liquid system indicated mesophases lamellar structure. The results of the microbiological analysis of mesophilic aerobic microorganisms (bacteria and fungi) revealed that the above formulation showed a biologic load <10 CFU/mL in all samples. In conclusion, liquid crystalline systems that have presented formation of a lamellar mesophases were developed. Furthermore, the formulation and products tested presented the adequate microbiological quality in accordance with official recommendations. Uniterms:Camellia sinensis/glycolic extract. Liquid crystal systems/cosmetic applications. Liquid crystal systems/characterization. Liquid crystal systems/microbiological control. INTRODUCTIONTechnological developments in the cosmetics industry and improved understanding of skin physiology have led to the incorporation of several active substances that are now commonly used in cosmetic formulations. Plant extracts, especially green tea glycolic extract, have been recently proposed for different purposes (Gianeti et al, 2013).Green tea, obtained from the plant Camellia sinensis, is rich in polyphenols, such as catechins. The most active catechin seems to be 3-gallate (-) epigallocatechin. Clinical studies show that green tea acts as a chemoprotectant and sunscreen agent with activities such as antioxidant, free radical scavenging, inhibiting the induction, initiation, promotion, and proliferation of carcinogenesis, antiinflammatory, antiangiogenic, inducer of apoptosis of carcinogen cells, metalloproteinase inhibitor, protector of the conversion of benign cells into malignant, and inhibitor of DNA damage (Pereira et al., 2009;Yun, Yang, 2015;Rodrigues et al., 2016).Studies performed by our research group compared pomegranate and green tea glycolic extracts (GTGE) in formulations and concluded that GTGE possessed greater bacterial growth inhibition measured as zone of inhibition than the other extracts, suggesting that GTGE has high antibacterial activity (Calixto et al., 2012).With the aim of obtaining final products with real benefits that can be perceived by consumers and to optimize the sensory attributes of these formulations, researchers have resorted to theories and scientific experimentations that were unique to the development of pharmaceutical preparations. Active substance delivery systems that were previously developed for pharmaceutical products (e.g., micro-and nanoemulsions and liquid-crystalline system...

Formulation and Evaluation of Liquid Crystal Emulsion Containing Extra Virgin Olive Oil as Skin Anti-Aging

“…The liquid crystal emulsion is a new type of emulsion which is different from conventional emulsion systems. This system is arranged regularly from surfactant and water molecules formed by the oil-water interface; this arrangement forms an emulsion with a liquid crystal structure which shows better usage than conventional emulsion systems in terms of stability, which is more stable compared to other emulsions because it offers some protection against photo or thermal degradation and increases high cutaneous hydration by increasing water intake in the corneal layer and also can delivering active ingredients with delayed-release in the target area [9]. The formation does not only depend on the emulsion formulation, but also the manufacturing process [10].…”

“…The formation does not only depend on the emulsion formulation, but also the manufacturing process [10]. In a previous study, Bernegossi et al [9], had formulated green tea extract into a liquid crystal system using silicone glycol copolymer as a surfactant. The result of the study showed that formulation with a high concentration of surfactants could produce a liquid crystal system with enhanced efficacy of the green tea extract.…”