Practical examples showcase the key role of plant-based lipids in the design of innovative sustainable specialty ingredients. Great diversity in plant origins and chemical transformations leads to great molecular diversity and explains why bio-based lipids are involved in broad ingredient categories such as biodegradable emollients, environmentally friendly surfactants, rheology modifiers and active ingredients. Choosing lipid structure, with varying fatty chain length, saturation level and branching, determines ingredient functionality and usage, as these vary, for instance in the case of surfactants, solubilizing, wetting, foaming and emulsifying properties (oil-in-water or water-in-oil). The lipid structure also impacts the ingredients’ final solid or liquid appearance. Now ready-to-use ingredients can be created and we can innovate with cold processable new cosmetic formulation concepts. Perhaps most importantly, optimal selection of lipid structure and composition can also drive consumer benefits in cosmetic ingredients, especially, the final sensory experience (for excipients) and biological efficacy (for active ingredients). Bio-based lipids lead to new ingredients with augmented performance and sensoriality.

Objective: Emotions play an important role in consumers' perception of a sensory experience. The objective of this work was to investigate the ability of basic skin care formulas (i.e. without interference of odour, colour and packaging) and pillar ingredients (i.e. emollients and rheology modifiers) to elicit emotions. Another objective was to track, as claimed by neurocosmetics, the possible effect of formulas to trigger emotions from their direct biochemical effects on the skin.Methods: Standard methodologies were mobilized, combining subjective and behavioural parameters (i.e. verbatim, prosody and gesture). Sense and Story methodology based on a collection of metaphoric verbatim was conducted after an induction phase. In addition, an experimental electrophysiological real‐time visualization method was tried as a first experience in cosmetics. Finally, the ability of formulations with emotional benefits to modulate the release of neuropeptides by sensory neurons was evaluated on a 3D human model (epidermis co‐cultured with sensory neurons).Results: Skin care formulas were shown to play a role in emotional potential and the types of emotion generated, while changing one ingredient mostly acted on the intensity of the emotions. Verbatim provided contrasted answers depending on the protocol, highlighting the interest of non‐verbal approaches to detect subtle effects. The in vitro model substantiated physiological effects of skin care formulas with emotional potential on human skin sensory neuron activity.Conclusion: Emotions were impacted by the change in ingredients and were better captured through non‐verbal methods.

Assessment of skin sensitization potential is mandatory for ingredients dedicated to topical applications. A battery of in vitro tests covering the key steps of the Adverse Outcome Pathway (AOP) for skin sensitization has been recommended to replace animal testing. However, despite international guidelines on in vitro methods, there is no universal approach defining their combination. The purpose of this work was to assess skin sensitization of botanical ingredients relying on a previously developed in vitro testing strategy. This tool focused on complex and poorly water-soluble substances, which were not already covered. Sixteen botanical extracts were tested in a sequential approach, starting with Sens-Is, supplemented by Organization for Economic Cooperation and Development (OECD) in vitro methods when necessary. The results on the selected well-known botanical sensitizers complemented the relevance of the strategy. Testing on experimental botanicals could detect skin sensitizers. In addition, phytochemistry was a determining support to identify and remove the components at the origin of the effect. Altogether, these results enlarged the scope of the methodology to various ingredient categories and chemical natures, contributing to place on the market new ingredients, safe for workers and end-users.

Sensitive skin is a common condition that affects many people in the world, especially women. This syndrome is defined by the occurrence of unpleasant sensations such as stinging and burning in response to stimuli that should not normally provoke such sensations. Coriander seed oil (CSO) is a 100% virgin oil of coriander seeds and boasts a specific composition of fatty acids, mainly petroselinic acid (60–75%). It has demonstrated its ability to regulate inflammation (NF-κB pathway) and nociception (TRPA1 pathway), two mechanisms supporting sensitive skin, in previous in vitro research. It was, therefore, a good candidate to be tested in vivo on sensitive skin conditions. A pilot clinical study was conducted to evaluate the effect of this ingredient on healthy women showing excessive skin reactions, mainly redness and discomfort when subjected to external stress. The results showed that the daily consumption of 200 mg of CSO for 28 days effectively reduced redness induced by stripping stress and itching induced by stinging stress. It also improved the perception of skin sensitivity and reactivity after 56 days of consumption. These clinical results confirmed that CSO is a promising ingredient to contribute to reducing reactivity in sensitive skin.

Skin penetration of an active pharmaceutical ingredient is key to developing topical drugs. This penetration can be adjusted for greater efficacy and/or safety through the selection of dosage form. Two emerging dosage forms, cream–gel and gel-in-oil emulsion, were tested for their ability to deliver diclofenac into the skin, with the target of maximising skin retention while limiting systemic exposure. Prototypes with varying amounts of solvents and emollients were formulated and evaluated by in vitro penetration testing on human skin. Cream–gel formulas showed better skin penetration than the emulgel benchmark drug even without added solvent, while gel-in-oil emulsions resulted in reduced diffusion of the active into the receptor fluid. Adding propylene glycol and diethylene glycol monoethyl ether as penetration enhancers resulted in different diclofenac penetration profiles depending on the dosage form and whether they were added to the disperse or continuous phase. Rheological characterisation of the prototypes revealed similar profiles of cream–gel and emulgel benchmark, whereas gel-in-oil emulsion demonstrated flow characteristics suitable for massaging product into the skin. This study underlined the potential of cream–gel and gel-in-oil emulsions for adjusting active penetration into the skin, broadening the range of choices available to topical formulation scientists.