Development and characterization of multiple emulsions for controlled release ofTrichilia catigua(Catuaba) extract

Evaluation of a multiple microemulsion from Trichilia catigua extract and the percutaneous penetration through skin by Phase-Resolved photoacoustic spectroscopy

Emulsion systems have been a breakthrough in cosmetic products, providing performance and effectiveness of products that use this technological strategy for drug delivery systems. In this sense, the microemulsion of the multiple emulsion W/O/W type containing a standardized extract of Trichilia catigua with high levels of polyphenols and antioxidants has great potential for cosmetic use. The aim of this study was to evaluate the formulations safety through the analysis of toxicity, comedogenicity, and histopathology in rabbits and apply the Phase-Resolved Photoacoustic Spectroscopy method to determine the formulation percutaneous penetration through the skin. The ex vivo experiments were performed in the ears of albino New Zealand rabbits treated twice a day for 14 days. The results of histological, hematological, and blood chemistry showed that the formulations are safe. Histopathological analysis showed no tissue reaction in any of the analyzed organs (liver and kidneys), confirming the absence of toxicity. Histological analysis showed that the formulations with extract of T. catigua demonstrated mild-moderately comedogenic and acanthosis compared to the control group. Inflammatory reactions, erythema, and desquamation were not observed in treated and controls animals. The phase-resolved photoacoustic spectroscopy method showed the penetration of the developed formulations throughout the rabbit's skin, identifying their absorption bands at the dermal side of the skin. In conclusion, the results of this study provide a step towards the application of the developed natural antioxidant encapsulated in a multiple microemulsion for skincare, concerned with the physical, chemical, and biological properties of the formulation.

Development and evaluation of Classical and Pickering emulsions containing crude or fractionated extracts of Libidibia ferrea pods

Objective: The development of medicinal plants for clinical use represents an important direction in biomedical research, despite the technological difficulties.Significance: The aim of this study was to compare pharmaceutical characteristics and in vitro release of Classical and Pickering emulsions containing crude or fractionated extracts of Libidibia ferrea.Methods: After evaluating the extract's solubility in formulation, a dispersion of hydroxypropyl methylcellulose (HPMC) was prepared in water. For Pickering emulsions, the aqueous phase was HPMC and the oil phase was Miglyol^® 812; for Classical emulsions, water with Tween^® 20 and Miglyol^® 812 with Span^® 80 were used for aqueous and oil phases, respectively. Crude or fractionated extracts were added to the aqueous phase (5% w/v). Both phases were heated (40 °C); then, the oil phase was poured into the aqueous phase and homogenized using an Ultra-Turrax. Emulsions were characterized for 90 days by pH, polyphenol content, phytomarker content, macroscopic characteristics, droplet size, and zeta potential.Results: These formulations displayed satisfactory stability for 90 days when stored at 25 °C. Regarding the investigation of rheological properties, Pickering emulsions displayed higher viscosity with lesser deformation than Classical emulsions. Moreover, the emulsions displayed similar in vitro release behavior.Conclusion: Based on the results of present study, the Pickering emulsions were obtainable and displayed higher stability than Classical emulsions. Additionally, maintenance of system integrity points to promising systems for delivery of active pharmaceutical ingredients in the internal phase, despite the complex chemical mixture added to the external phase.

Encapsulating plant ingredients for dermocosmetic application: an updated review of delivery systems and characterization techniques

Today, there is a rising demand and ongoing search for novel plant-derived phytochemicals in the cosmetic market owing to the growing consumer expectations worldwide for green and natural health products. Various plant ingredients, including polyphenols, oils, volatile oils, vitamins and other herbal extracts, have been extensively used in herbal cosmetics. Recent advances in encapsulation technologies have greatly improved their chemical stability, biocompatibility, skin permeability and dermocosmetic efficiency when applied topically. This comprehensive review summarizes the up-to-date information on encapsulated plant ingredients tailored for dermocosmetic application with a focus on the development of novel delivery systems. An overview of the commonly used techniques for carrier characterization, performance-related properties and toxicological evaluation is also included, which might provide guidance for researchers to select or develop appropriate assay systems.