Compendium of the most significant studies with reference to properties, intake, effects.

Merat, E., Roso, A., Dumaine, M., & Sigurani, S. (2022). Sensory evaluation of cosmetic functional ingredients. In Nonfood Sensory Practices (pp. 197-216). Woodhead Publishing.

Abstract. This chapter is dedicated to the sensorial assessment of raw materials that are the functional components in cosmetic products. After discussing the necessary safety and regulatory framework, readers will discover how to standardize any ingredient conditions such as evaluation, thickeners, emulsifiers, texturing, or softness agents. While the main application is in the field of skin care, there are also other cases for hair care and foaming ingredients. Some protocols and results are shown as examples for triangulation, ranking, profiling, and illustrate the effect of one ingredient in a formulation from an innovation or quality control context.

Huang, Z. (2009). Alkane metathesis via tandem catalysis (Doctoral dissertation, The University of North Carolina at Chapel Hill).

Abstract. Alkane metathesis (AM) has potentially tremendous applicability via converting low-value alkanes (C3-C9) from the Fisher-Tropsch process into linear alkanes in the diesel fuel range (C10-C19). A well-defined and highly efficient tandem catalytic system for the metathesis of n-alkanes has been developed. The system is comprised of one pincer Ir catalyst that effects alkane dehydrogenation and olefin hydrogenation, and a second catalyst for olefin metathesis. The catalytic system shows complete selectivity for linear alkane products. ...

Vukašinović, M., Savić, S., Cekić, N., Ilić, T., Pantelić, I., & Savić, S. D. (2023). Efficient Development of Green Emulsifier/Emollient-Based Emulsion Vehicles: From RSM Optimal Experimental Design to Abridged In Vivo Assessment. Pharmaceutics, 15(2), 486.

Abstract. Since natural-origin, sustainable ingredients are preferred by modern consumers, novel emulsifiers and emollients keep entering the market. This study hypothesizes that a combination of in silico, instrumental tools and simplified sensory studies could be used to efficiently characterize emulsions in a shorter timeframe. A total of 22 rather simple o/w emulsions were prepared by a time/energy-saving emulsification process. A natural mixed emulsifier (Lauryl Glucoside/Myristyl Glucoside/Polyglyceryl-6 Laurate) and two emollients (both with INCI name C15–19 Alkane) were used. The performed D-optimal experimental design within the response surface method (RSM) significantly narrowed down the number of samples about to enter the stage of texture, friction and sensory studies to the samples comprising 30% of a respective Emogreen emollient and 2% or 3% of the emulsifier. The sample comprising 2% emulsifier/30% Emogreen® L15 showed significantly higher firmness (42.12 mN) when compared to the one with 2% emulsifier/30% Emogreen® L19 (33.62 mN), which was somewhat unexpected considering the emollients’ inherent viscosity values (4.5 mPa·s for L15 and 9 mPa·s for L19). The sample with 2% emulsifier/30% Emogreen® L19 managed to maintain the lowest friction, while the one with 3% emulsifier/30% Emogreen® L19 released its full lubricating potential in the second part of the measurement (30–60 s). The obtained results revealed the strengths and weaknesses of each formulation, narrowing down their possible applications in the early development stage.

Bom, S., Fitas, M., Martins, A. M., Pinto, P., Ribeiro, H. M., & Marto, J. (2020). Replacing synthetic ingredients by sustainable natural alternatives: a case study using topical O/W emulsions. Molecules, 25(21), 4887.

Abstract. With the increasing debate on sustainability, there is a strong market trend to formulate more sustainable products for topical application. Several studies emphasize the potential applications of natural, organic, or green chemistry-derived ingredients, but comparative studies between conventional ingredients and sustainable alternatives are lacking. This type of study is considered an excellent baseline and time-saving strategy for future studies. In addition, one of the main challenges of replacing ingredients by sustainable alternatives in topical vehicles is to maintain high-quality products. Thus, the main goal of this research study was to create a well-defined strategy supported by specific experimental data for the development of sustainable topical vehicles with high-quality standards. The study was designed to evaluate the effects of replacing conventional ingredients (e.g., hydrocarbons, silicones, and preservatives) by sustainable ones on the physical, chemical, and microbiological features of topical emulsions. Additionally, in vivo assessment studies were performed to evaluate the safety, biological efficacy, and sensorial aspects of the developed formulations. The results obtained showed that the replacement of ingredients by sustainable alternatives has an effective impact on the physicochemical and structural properties of the emulsions, mainly on their rheological behavior. However, using appropriate strategies for ingredient selection and rheological adjustment, it is possible to overcome some barriers created by the use of natural raw materials, thus developing appealing and high-quality sustainable topical vehicles.

Savic, S. M., Cekic, N. D., Savic, S. R., Ilic, T. M., & Savic, S. D. (2021). ‘All‐natural’anti‐wrinkle emulsion serum with Acmella oleracea extract: A design of experiments (DoE) formulation approach, rheology and in vivo skin performance/efficacy evaluation. International Journal of Cosmetic Science, 43(5), 530-546.

Abstract. Objective. The growing consumers’ preferences and concerns regarding healthy ageing, youthful skin appearance, environmental protection and sustainability have triggered an ever-increasing trend towards natural, eco-friendly and ethically sourced anti-ageing products. Accordingly, this paper describes design and evaluation of novel, safe, effective and high-quality emulsion serums, completely based on ingredients of natural origin, intended for improving facial fine lines and wrinkles....Results. Rheological characterization revealed favourable shear-thinning flow behaviour with yield point, and dominating elastic character (storage modulus G’ > loss modulus G") in both amplitude and frequency sweeps, which together with relatively small structural change obtained in DMTA test indicated overall satisfying rheological and stability properties of formulated serums. From the established design space, and taking into account formulation cost and carbon footprint, promising model serum (desired/optimal apparent viscosity, yield point and loss factor, rather small and constant structural change), containing 15% of emollients and 1% of emulsifier, was chosen for in vivo evaluations. Screening of skin irritation effects revealed the absence of potential irritancy of investigated serum, suggesting overall satisfying skin tolerability/preliminary safety. Silicone skin replica image analysis demonstrated noticeable reduction/improvement in all measured skin wrinkle parameters after only 2 weeks of test serum application in periorbital and perioral areas, indicating its rapid and beneficial effects on the facial expression lines and wrinkles. Conclusion. Altogether, the results corroborate the promising potential of the developed Acmella oleracea extract-loaded emulsion serum as safe, effective and non-invasive natural anti-wrinkle product