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The mitigation of damaged hair conditions involves the application and penetration of substances to stabilize broken bond sites, restore lipids and proteins, reinstate hydrophobicity, and recover hair mechanical properties. Vegetable oils, in general, exhibit a list of advantageous characteristics much desired by consumers, given the associated benefits for hair fibers. While coconut oil is highly popular in the hair care market and extensively studied for its ability to diffuse through the hair cortex, the effects of avocado and argan oil on the internal structure of hair and their potential benefits remain underexplored. Tensile and fatigue tests, as well as Raman spectroscopy, were carried out to investigate the interaction of these three oils with virgin and bleached Caucasian hair. The oils were applied in sufficient amounts directly to hair tresses and maintained for 24 h at 25 °C. Our results show that the three oils successfully diffused and interacted with the cortical region of the hairs. Their impact on hair mechanical properties depends on the level of damage and humidity conditions. In virgin hair, coconut and avocado oil reinforce the hydrophobic barrier of the cellular membrane complex, preventing water from causing intense perturbation of the mechanical properties, leading to increased stiffness and break stress. Meanwhile, due to the high degree of unsaturation of its fatty acid chains, argan oil increases water absorption, resulting in losses in hair resistance. When bleached, the hydrophilicity of the hair fiber increases, determining more affinity for argan oil. Consequently, the affinity with water is also elevated, causing increased fragility to mechanical stress. The analyzed vegetable oils are not always beneficial for hair care. Their specific chemical characteristics and hair conditions will influence the final results and should be taken into consideration in hair care product development.

Black pepper, a commonly utilized culinary condiment, holds significant importance in Ayurvedic and Chinese medicinal practices due to its various biological benefits, including antioxidant, antimicrobial, and anti-inflammatory properties. To amplify these attributes and enhance their efficacy in formulations, the utilization of nanocarriers presents a promising approach. Thus, the objective of this study was to obtain a pepper extract, evaluate its constituents, and encapsulate it in polymeric nanoparticles. The ethanol extract of the grains powder had a higher concentration of piperine and better antioxidant activity when compared to whole grains. Pepper extract encapsulation efficiency in terms of piperine concentration was 84.8 ± 3.5%, and a sustained and prolonged release profile was observed, as well as other studies in the literature using polycaprolactone (PCL). The presence of the extract did not change the instability index and the sedimentation velocity of the nanoparticles, as well as the polydispersity index and the zeta potential of nanoparticles. However, there was a difference in the mean size and concentration of particles. This study highlights the potential of PCL nanoparticles as a promising delivery system for black pepper extract, which could have various applications in the cosmetic and pharmaceutical industries, maximizing the benefits of black pepper extract.

Resveratrol is a polyphenolic phytoalexin, whose main natural sources are red grapes, red wine, berries, and peanuts. When applied to the skin, resveratrol evidences a good penetrating capacity and low degradation compared to the oral route, allowing for a longer and improved topical effect. This bioactive molecule has been gaining interest in dermo-pharmacy and cosmetics for the prevention and treatment of skin alterations. Its inherent meritorious biomedical potentials, including anti-aging, photoprotective, estrogen-like, skin-whitening, anti-acne, wound healing, anti-scarring, antimicrobial, and anti-skin cancer properties are the most evident. However, resveratrol evidences stability hurdles, becoming an unstable molecule when exposed to ultraviolet radiation. Several technological strategies have been developed to improve its stability, efficacy, and safety. We have described the main topical properties of resveratrol, and the involved mechanisms of action, and a great focus was placed on the technological strategies for the efficient application of resveratrol in dermatological and cosmetic formulations, including nanotechnology.

The use of materials and products that improve appearance and provide comfort and well-being goes back to the beginning of civilization. Cosmetics is an evolving market that has increasingly focused on innovative technological approaches. Nanotechnology is one of the most revolutionary and promising fields for the development of novel and enhanced cosmetic products, owing to the remarkable multifunctional characteristics and effects of nanomaterials (NMs). Their application, however, also raises potential safety concerns. Some of these concerns can be addressed by determining the type of NMs used, as well as their stability, potential for skin absorption, route of exposure, and how they are formulated into cosmetic products. To guarantee such safety, cosmetic products containing NMs, must comply with European regulatory provisions, particularly the European Regulation (EC) n.° 1223/2009 of the European Parliament and of the Council. Hence, this review comprises all the particularities of NMs, their influence on human health, challenges towards environmental sustainability, and strategies to harmonize policies with the aim to normalize their application in cosmetics.

Nanomaterials use in cosmetics is markedly enhancing, so their exposure and toxicity are important parameters to consider for their risk assessment. This review article provides an overview of the active cosmetic ingredients used for cosmetic application, including dermal cosmetics and also hair dye cosmetics, as well as their safety assessment, enriched with a compilation of the safety assessment tests available to evaluate the different types of toxicity. In fact, despite the increase in research and the number of papers published in the field of nanotechnology, the related safety assessment is still insufficient. To elucidate the possible effects that nanosized particles can have on living systems, more studies reproducing similar conditions to what happens in vivo should be conducted, particularly considering the complex interactions of the biological systems and active cosmetic ingredients to achieve newer, safer, and more efficient nanomaterials. Toward this end, ecological issues and the toxicological pattern should also be a study target.