Sunscreens: An overview and update

New trends on personalized sunscreens

BACKGROUND/PURPOSE

Nowadays, there are emerging trends in customized and personalized photoprotection, focusing on the innovative approaches to enhance sun protection efficacy tailored to individual needs.

METHODS

We conducted an electronic search of the following databases: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Skin Group Specialised Skin Register, and TESEO. Specific search terms related to personalized photoprotection and the variables of age, genetic predisposition, skin phototype, photodermatosis, and physiological conditions such as pregnancy, as well as lifestyle habits were used.

RESULTS/CONCLUSION

The article highlights the challenges and opportunities in adopting personalized photoprotection strategies, aiming to promote skin health and prevent the harmful effects of UV radiation in the era of precision medicine.

In vitro synthesis of oryzamutaic acid H using recombinant L-lysine ε-dehydrogenase from Agrobacterium tumefaciens

Oryzamutaic acids, possessing a nitrogen-containing heterocyclic skeleton, have been isolated and identified from a rice mutant. Although oryzamutaic acids are expected to be functional ingredients, their functionality is difficult to evaluate, because of their wide variety and presence in trace amounts. Furthermore, how oryzamutaic acid is synthesized in vivo is unclear. Therefore, we developed a simple enzymatic synthesis method for these compounds in vitro. We focused on L-lysine ε-dehydrogenase (LysDH) from Agrobacterium tumefaciens, which synthesizes α-aminoadipate-δ-semialdehyde-a precursor of oryzamutaic acids. LysDH was cloned and expressed in Escherichia coli. Analysis of activity revealed that LysDH catalyzed the synthesis of oryzamutaic acid H at neutral pH in vitro. We synthesized 1.6 mg oryzamutaic acid H from 100 mg L-lysine. The synthesized oryzamutaic acid H exhibited UVA absorption, stability of temperature, and stability at a wide pH range. To our knowledge, this study is the first to report the enzymatic synthesis of oryzamutaic acid H in vitro and provides a basis for understanding the mechanisms of oryzamutaic acid synthesis in vivo.

Efficacy of ceramide-containing sunscreen on skin barrier

BACKGROUND

UV rays not only cause oxidative damage to the skin, but also damage its barrier function. The use of sunscreen is crucial in preventing skin from UV radiation, but it may have an impact on the function of the skin barrier. While much research has focused on the protective effects of sunscreen against UV oxidative damage, little is known about the impact of daily sunscreen use on the skin barrier.

OBJECTIVE

This study mainly investigated the changes in skin barrier function of volunteers (including those with sensitive skin) before and after using a ceramide-containing sunscreen.

METHODS

A total of 60 volunteers used SPF30 sunscreen containing ceramide every morning. Using non-invasive methods to detect skin barrier changes in TEWL, hydration, facial redness based on VISIA-CR image, and Erythema index (EI) value after 4 weeks of using ceramide-containing sunscreen. Adverse reactions were also assessed.

RESULTS

After 4 weeks of using ceramide-containing sunscreen, significant reductions were observed in skin redness with both an 11.89% decrease in a* value and a 5.68% decrease in skin EI, while there was also a significant decrease in transepidermal water loss (TEWL) with a reduction of 22.96%, and a significant increase in skin hydration with a 21.96% increase in the moisture content of the stratum corneum. No adverse events occurred during the entire testing process.

CONCLUSION

Daily application of ceramide-containing sunscreen can increase skin hydration while enhancing the function of the skin barrier.

Boosting the effectiveness of UV filters and sunscreen formulations using photostable, non-toxic inorganic platelets

We have studied the size-dependent optical scattering of aqueous suspensions containing Mg2Al-LDH platelets, which exhibit high total- and side-scatterings. By incorporating 3 wt% Mg2Al-LDH platelets (280 nm) in a commercial sunscreen formulation, we achieved a twofold Sun Protection Factor boost, providing a promising, high-efficient and non-toxic strategy to enhance sunscreen effectiveness.

Long-lasting UV-blocking Mechanism of Lignin: Origin and Stabilization of Semiquinone Radicals

Semiquinone (SQ) radicals play a critical role in the long-lasting UV-blocking application of lignin, while their origin and stable structure are unclear. Here, the organosolv lignin extracted from poplar (OL-P) is self-assembled into normal micelles (LNM) with more phenolic hydroxyl groups on the surface, and reverse micelles (LRM) with more methoxyl groups on the surface. After 12 h UV irradiation, the SQ radical contents in LNM and LRM increase 33% and 78% respectively. The performance of LNM based sunscreen keeps upswinging due to radical stabilization of phenolic hydroxyl groups. LRM based sunscreen experiences a gradual decrease after reaching maximum UV absorbance due to the quick generation and over oxidation of SQ radicals. Density functional theory (DFT) simulations reveal that methoxyl groups in OL-P has bigger bond length and smaller bond dissociation enthalpy than phenolic hydroxyl groups, and are easy to form SQ radicals. The Gibbs free energy (ΔG) needed for SQ-quinone transformation is above 26.10 kcal mol.-1 , while that for SQ-hydroquinone transformation is below -66.78 kcal mol.-1 . Hydroquinone is the stable structure of SQ radicals. This work discloses the origin and stable structure of SQ radicals in lignin under UV irradiation, and provides an important guidance for its long-lasting UV-blocking application.

Clinical Applications of Sunscreens and Formulation Advancements

Sunscreens cover the big market ratio in terms of cosmetic applications, but the therapeutic necessity of sunscreen still needs to be uncovered in the clinical context. Clinically, sunscreens are being employed more often nowadays as a result of the rising consequences of skin malignancies and the photodamaging effects of UV radiation. Sunscreens are essential to prevent aging by shielding the skin from the harmful effects of ultraviolet (UV) radiation. Over the recent decades, there has been a significant evolution in the usage of sunscreens as photo protectants. The demand for sunscreen formulations will inevitably rise as more people become aware of the protection that sunscreens provide against tanning, photoaging, non-melanoma skin cancers, premalignant skin lesions, and skin melanomas. The novel contemporary formulation techniques are also beneficial in enhancing the product's aesthetic look and quality. Recently, regulatory agencies have also started paying attention to the regulation of the clinical application, efficacy, and safety parameters related to sunscreen. This review underlines the pathophysiological response of UV exposure with the therapeutic applications of sunscreen in various dermatological conditions and the recent formulation advancements in the development of sunscreen.

Anthraquinones from Rhamnus alaternus L.: A Phytocosmetic Ingredient with Photoprotective and Antimelanogenesis Properties

The purpose of the present work was to develop a phytocosmetic sunscreen emulsion with antioxidant activity and an anti-melanogenic effect, containing an anthraquinone-enriched extract of Rhamnus alaternus (A.E.). Our findings demonstrated that A.E. decreased the levels of reactive oxygen species, DNA damage, and malondialdehyde induced by UVA in human keratinocytes and melanocytes. Furthermore, the calculated SPF value in vitro of the cream containing A.E. was 14.26±0.152. Later, it was shown that A.E. extract had an inhibitory effect on the amount of melanin. This extract could also reduce B16F10 intracellular tyrosinase activity. Besides, docking studies were carried out to provide a logical justification for the anti-tyrosinase potential. The findings showed that, A.E. may provide protection against UVA-induced oxidative stress and could be thought of as a viable treatment for hyperpigmentation disorders.

Recombinant production of a highly efficient photolyase from Thermus thermophilus

Ultraviolet (UV) radiation from sunlight can damage DNA, inducing mutagenesis and eventually leading to skin cancer. Topical sunscreens are used to avoid the effect of UV irradiation, but the topical application of DNA repair enzymes, such as photolyase, can provide active photoprotection by DNA recovery. Here we produced a recombinant Thermus thermophilus photolyase expressed in Escherichia coli, evaluated the kinetic parameters of bacterial growth and the kinetics and stability of the enzyme. The maximum biomass (𝑋𝑚𝑎𝑥 ) of 2.0 g L-1 was reached after 5 h of cultivation, corresponding to 𝑃X  = 0.4 g L-1 h. The µ𝑚𝑎𝑥 corresponded to 1.0 h-1 . Photolyase was purified by affinity chromatography and high amounts of pure enzyme were obtained (3.25 mg L-1 of cultivation). Two different methods demonstrated the enzyme activity on DNA samples and very low enzyme concentrations, such as 15 µg mL-1 , already resulted in 90% of CPD photodamage removal. We also determined photolyase kM of 9.5 nM, confirming the potential of the enzyme at very low concentrations, and demonstrated conservation of enzyme activity after freezing (-20°C) and lyophilization. Therefore, we demonstrate T. thermophilus photolyase capacity of CPD damage repair and its potential as an active ingredient to be incorporated in dermatological products.

Influence of environmental stresses on the durability of slag-based alkali-activated cement crusts for wind erosion control

Wind erosion is a significant environmental challenge in arid and semi-arid regions, and artificial crust creation on the soil surface has emerged as an effective approach to mitigate this phenomenon. Various methods of crust formation have been proposed to combat wind erosion in these regions. However, a comprehensive study assessing the durability of these crusts against environmental stresses has been lacking. Hence, the primary objective of the present study is to address this critical issue by evaluating the erodibility and surface strength of alkali-activated slag crusts in response to various environmental stressors. These stressors encompass ultraviolet radiation, heating and cooling cycles, wetting and drying cycles, and freezing and thawing cycles. Through wind tunnel tests, erosion rates were measured under different wind velocities and saltation bombardment conditions, while penetrometer tests were conducted to analyze surface strength. The results demonstrate that alkali-activated cementation produced robust crusts, exhibiting an impressive reduction of over 99.9 % in erosion rates compared to untreated samples. However, the introduction of environmental stresses led to a fivefold increase in erosion rates. Freeze and thaw cycles had the most detrimental effect on the alkali-activated cement crusts while heating and cooling cycles had a relatively minor impact. The wetting and drying cycles and UV radiation ranked second and third, respectively, in terms of their destructive effects on crust erodibility. Despite the observed effects, the crusts maintained their efficiency even when subjected to severe environmental stresses. Notably, the erosion rate of the treated crusts after enduring the most severe studied stress, that is five freeze and thaw cycles, was over 250 times lower than that of the untreated samples.

Green Synthesis of Zein-Based Nanoparticles Encapsulating Lupulone: Antibacterial and Antiphotoaging Agents

Prolonged skin exposure to UV radiation may result in sunburn, with possible inflammatory and oxidative stress to the skin, skin photoaging, photocarcinogenesis, even DNA damage, and apoptosis if sunscreen protection is not used. Due to the advantages that they offer, high encapsulation capability, increased stability of encapsulated bioactive agents, and release control, nanoparticulate materials have been used in sunscreens despite the hazard that they present: their capacity to penetrate the skin causing toxic side effects (especially the chemical sunscreens). The present study reports the preparation of nanoparticulate composites containing only GRAS substances and using an eco-friendly, inexpensive procedure. The ingredients used have properties that are beneficial to the skin. Zein (Z), a prolamin-rich protein from corn, is biodegradable and biocompatible, is a moisture attractor, and shows effective absorption by cells. Lupulone (L), extracted from hops, is an antibacterial and antioxidant agent that has a stimulating effect on the collagen production in the body due to its content of phytohormones. Gum arabic (GA) is a natural glycoprotein used in beverages and cosmetics as an emulsifier/stabilizer. Composite matrices containing Z/GA/L were prepared using a simple method (antisolvent), which replaces the flammable solvent ethanol with aqueous propylene glycol. The nanocomposites were characterized by FTIR, composition, encapsulation efficiency, and loading capacity for L, size, zeta potential, and morphology (SEM). Their biological activity was investigated as well. The zein-based nanoparticles showed antioxidant and antimicrobial effects (even some synergistic, unexpected behavior) and modulatory activity on the matrix metalloproteinase MMP-1. Due to their properties, the nanoparticles discussed herein show potential for use in formulations for the skin, especially for mature skin, replacing chemical substances with potential side effects used typically in topical delivery systems.

Recent advances in lignin antioxidant: Antioxidant mechanism, evaluation methods, influence factors and various applications

Lignin, a by-product of processing lignocellulosic materials, has a polyphenolic structure and can be used as an antioxidant directly or synergistically with synthetic types of antioxidants, leading to different applications. Its antioxidant mechanism is mainly related to the production of ROS, but the details need to be further investigated. The antioxidant property of lignin is mainly related to the content of phenolic hydroxyl group, but methoxy, purity will also have an effect on it. In addition, different methods to detect the antioxidant properties of lignin have different advantages and disadvantages. In this paper, the antioxidant mechanism of lignin, the methods to determine the antioxidant activity and the progress of its application in various fields are reviewed. In addition, the current research on the antioxidant properties of lignin and the hot directions are provided, and an outlook on the research into the antioxidant properties of lignin is provided to broaden its potential application areas.

How vitamins act as novel agents for ameliorating diabetic peripheral neuropathy: A comprehensive overview

Diabetic peripheral neuropathy (DPN) is a pervasive and incapacitating sequela of diabetes, affecting a significant proportion of those diagnosed with the disease, yet an effective treatment remains elusive. Vitamins have been extensively studied, emerging as a promising target for diagnosing and treating various systemic diseases, but their role in DPN is not known. This review collates and synthesizes knowledge regarding the interplay between vitamins and DPN, drawing on bibliographies from prior studies and relevant articles, and stratifying the therapeutic strategies from prophylactic to interventional. In addition, the clinical evidence supporting the use of vitamins to ameliorate DPN is also evaluated, underscoring the potential of vitamins as putative therapeutic agents. We anticipate that this review will offer novel insights for developing and applying vitamin-based therapies for DPN.

Effects of Commercial Sunscreens on Survival, Reproduction and Embryonic Development of the Aquatic Snail Biomphalaria glabrata (SAY, 1818)

Over the past few years, there has been a significant increase in the use of sunscreens. Consequently, the occurrence in aquatic environments of ultraviolet filters has also increased. The present study aims to evaluate the toxicity of two commercial sunscreens to the aquatic snail Biomphalaria glabrata. Acute assays were performed with adult snails exposed to solutions of the two products in synthetic soft water. Reproduction and development assays were carried out, involving individual adult and egg masses exposure to assess fertility and embryonic development. Sunscreen A showed a LC₅₀-96 h of 6.8 g/L and reduction in number of eggs and egg masses per individual in the concentration of 0.3 g/L. Sunscreen B presented higher malformation rates in 0.4 g/L with 63% of malformed embryos. Results indicate that the formulation used in sunscreens is an important factor in aquatic toxicity and needs to be evaluated before the final product is commercialized.

Perspectives of topical formulations for melasma

Melasma is acquired hyperpigmentation that mainly affects the face, can cause negative changes in self-esteem, and mostly affects women. Treatment is difficult, and different drugs can be used in mono or combination therapy. In this article, we present a brief overview of melasma, how to evaluate it, and a synthesis of the most commonly used topical therapies and their indications, including sunscreens, pharmacological agents, and plant extracts. Hydroquinone (4%) in monotherapy or combined with corticosteroids (dexamethasone and fluocinolone acetonide) and retinoids (tretinoin); arbutin (1%); methimazole (5%); kojic (2%), azelaic (20%), and tranexamic (5%) acids are the pharmacological agents that stand out. Correct application of these substances determines a variable improvement in melasma but often causes adverse reactions such as erythema, itching, and burning at the application site. Vitamin C can contribute to the reduction of melasma and have little or no adverse effects while sunscreens are normally used as coadjuvant therapies. In conclusion, we have compiled specific topical therapies for treating melasma and discussed those that are the most used currently. We consider it important that prescribers and researchers evaluate the best cost-benefit ratio of topical therapeutic options and develop new formulations, enabling efficacy in the treatment with safety and comfort during application, through the reduction of adverse effects.

The impact of blue light and digital screens on the skin

INTRODUCTION

The skin is frequently subjected to a variety of environmental trauma and stress. It is unavoidably subjected to blue light due to the increased use of electronic equipment, including indoor lighting and digital gadgets like smartphones and laptops, which have a range of detrimental effects. The method of action and numerous harmful consequences of blue light on the skin are the main subjects of this review.

MATERIALS AND METHODS

A literature search has been performed using PubMed, GoogleScholar and EmBase databases and an updated review on the topic has been presented.

RESULTS

Numerous studies have shown that being exposed to blue light accelerates the aging process and produces cutaneous hyperpigmentation. It also modifies the circadian rhythm. The two main molecules that mediate cellular responses to blue light are nitric oxide (NO) and reactive oxygen species. However, the precise process is still not fully known.

CONCLUSION

These negative consequences may eventually cause more general skin damage, which may hasten the aging process. At times, skin protection may be crucial for protection against blue light.

A transparent kaolinite-loaded zinc oxide nanocomposite sunscreen with UV shielding rate over 99% based on bidirectional dispersion

Nano-sized TiO₂and ZnO are the most efficient and widely used inorganic sunscreen, but they still have some drawbacks including agglomeration, delamination, clogging pores and high cost. In this study, a kaolinite-loaded zinc oxide nanocomposite sunscreen was prepared and the key technical problems in application of inorganic nano-sized sunscreens was solved. The synthesized kaolinite-loaded zinc oxide nanocomposite was characterized by XRD, SEM, EDS, XRF and UV-vis spectrophotometry. The SEM image of the nanocomposite suggests that agglomeration of nano-ZnO is avoided by bidirectional dispersion of superfine kaolinite powder and nano-ZnO. Nano-effect and UV shielding rate are enhanced and the nanocomposite sunscreen possesses UV shielding efficiency of 1 + 1 > 2. The UV shielding rate of the nanocomposite sunscreen is greater than 99%, only 10% addition of it endows ordinary skin care products with excellent UV protective efficacy. Moreover, the content of nano-ZnO is reduced by half through introduction of kaolinite, the cost of the sunscreen is lowered, delamination and pore clogging are avoided. This work provides a technical approach for producing stronger, safer and more economical popularized anti-UV skincare products.

Transport of emerging organic ultraviolet (UV) filters in ceramic membranes: Role of polyethylene (PE) microplastics

Microplastics can be considered potential carriers of emerging organic ultraviolet (UV) filters due to their considerable adsorption capacity in wastewater treatment. The adsorption behavior of organic UV filters, which are commonly contained in personal care products to preserve the skin against UV radiation, onto polyethylene (PE) microplastics were systematically studied to investigate their combined effects. Kinetics and isotherm analyses revealed that the adsorption of four organic UV filters onto PE microplastic surfaces followed a multi-rate and a heterogeneous multi-layer pattern. Several factors including salinity, microplastic size, and dosage also influenced the adsorption efficiency due to hydrophobic interactions. A bench-scale cross-flow ceramic membrane filtration experiment was investigated to evaluate the role of PE microplastics on the retention performance of organic UV filters. The retentions for organic UV filters were 34.2%-37.8% in the non-existence of PE microplastics. Conversely, organic UV filter retentions were significantly increased up to 82.2%-97.9% when they were adsorbed onto the PE microplastics, which were almost completely retained by the ceramic membrane. Therefore, organic UV filters can likely migrate and eventually be carried by PE microplastics, thus increasing the retention of both emerging organic UV filters and microplastics prior to discharge from wastewater treatment facilities.

Environmental impacts due to the use of sunscreen products: a mini-review

Sunscreen use has increased in recent years, as sunscreen products minimize the damaging effects of solar radiation. Active ingredients called ultraviolet (UV) filters or UV agents, either organic or inorganic, responsible for defending skin tissue against harmful UV rays, are incorporated in sunscreen formulations. UV agents have a serious impact on many members of bio communities, and they are transferred to the environment either directly or indirectly. Many organic UV filters are found to be accumulated in marine environments because of high values of the octanol/water partition coefficient. However, due to the fact that UV agents are not stable in water, unwanted by-products may be formed. Experimental studies or field observations have shown that organic UV filters tend to bioaccumulate in various aquatic animals, such as corals, algae, arthropods, mollusks, echinoderms, marine vertebrates. This review was conducted in order to understand the effects of UV agents on both the environment and marine biota. In vivo and in vitro studies of UV filters show a wide range of adverse effects on the environment and exposed organisms. Coral bleaching receives considerable attention, but the scientific data identify potential toxicities of endocrine, neurologic, neoplastic and developmental pathways. However, more controlled environmental studies and long-term human use data are limited. Several jurisdictions have prohibited specific UV filters, but this does not adequately address the dichotomy of the benefits of photoprotection vs lack of eco-friendly, safe, and approved alternatives.

In Situ Assay of Interfacial Interaction between ZnO Nanoparticles and Live Cell Disturbed by Surfactants

The interfacial interaction between pollutants and organisms is a critical process in controlling the environmental fates of pollutants; however, in situ assay of the interaction is still a great challenge. Here, in situ determination of dissociation constants (K_d) for ZnO nanoparticles (ZnO NPs) from live algal cells disturbed by different-charged surfactants was established using microscale thermophoresis (MST). Moreover, in situ measurement of the adhesion force between the ZnO NPs probe and live single cell was performed using an atomic force microscope (AFM). Results showed that the cationic cetyltrimethylammonium chloride (CTAC) and anionic sodium dodecylbenzenesulfonate (SDBS) increased but nonionic Triton X-100 (TX-100) decreased the adhesion of ZnO NPs on cells. However, the force signature exhibited a smooth single retracted peak at short distances in the SDBS- and TX-100-treated groups, distinguished from the "see-saw" pattern peak in the CTAC-treated groups. The extended Derjaguin-Landau-Verway-Overbeek (XDLVO) calculation further confirmed that SDBS and TX-100 mainly disturbed the short-range hydration on the NP-cell interface, while CTAC reduced the long-range electrostatic repulsion. Furthermore, an excellent linear correlation between Zn bioaccumulation and two parameters (K_d and adhesion force) indicated that NP-cell interfacial interactions affected Zn bioaccumulation. Thus, in situ assay provides a quantitative basis for the pollutant-organism interfacial interaction to evaluate the environmental fate and ecological risk of pollutants.

Antitumor/anti-angiogenesis efficacy of epigallocatechin gallate nanoformulated with antioxidant in melanoma

Aim: Epigallocatechin gallate (EGCG) derived from green tea has poor stability; therefore, to enhance its bioavailability and anticancer efficiency, we synthesized three different nanoformulations. We hypothesized that these three nanoformulations of EGCG (nano-EGCG) would enhance EGCG’s stability and improve its anticancer and antiangiogenic activity against melanoma compared with free EGCG. Methods: We prepared nano-EGCG using a copolymerization method with the UV blocker ZnO and the antioxidants lycopene and olive oil. Results: The different nano-EGCG formulation exhibited improved EGCG stability and greater suppression of melanoma growth than free EGCG. Nanoformulation preparation methods efficiently prevented the loss of EGCG activity and are a favorable approach for the treatment of melanoma. Conclusion: Nano-EGCG formulations had enhanced stability and produced greater suppression of melanoma tumor growth and angiogenesis compared with free EGCG.

Peptide Cysteine Thiols Act as Photostabilizer of Avobenzone through Stabilising the Transition State of Keto-enol Tautomerization

Photostabilizers have been used to impart stability to an FDA-approved chemical UV-A filter avobenzone against the UV-A radiations and sunlight. The thiol group of glutathione plays a critical role in imparting the photostabilization activity of glutathione on avobenzone. The current report aims to evaluate the photostabilization activity of multiple thiols containing cysteine peptides on avobenzone. Cysteine-tripeptide and cysteine-pentapeptide were chemically synthesized and characterized using mass spectrometry. Synthetic peptides were assessed for their photostabilization activity on the enolic-form of the avobenzone under natural sunlight using UV-spectroscopy in both protic and aprotic solvents. Unlike glutathione which has pronounced activity in protic solvents, cysteine-pentapeptide exhibits similar photoprotection activity in both protic and aprotic solvents. Computational calculations using DFT suggest that peptide cysteine thiols may assist in the reversal of the photoketonization process of avobenzone thereby exhibiting the photoprotection activity to the enolic-form of avobenzone. Peptide cysteine thiols lower the activation energy barrier of keto-to-enol tautomerization of avobenzone by 30 kcal/mol by assisting the proton shuttle through a six-membered transition state. The current report emphasizes the applications of peptide thiols in cosmetics and may help in the development of peptides as aesthetic medicines.

Photostability of the deprotonated forms of the UV filters homosalate and octyl salicylate: molecular dissociation versus electron detachment following UV excitation

While common molecular anions show a strong propensity to undergo electron detachment upon UV excitation, this process often occurs in competition with molecular ion dissociation. The factors that affect the balance between these two major possible decay pathways have not been well understood to date. Laser photodissociation spectroscopy of the deprotonated forms of the UV filter molecules, Homosalate (HS) and Octyl Salicylate (OS), i.e. [HS - H]^- and [OS - H]^-, was used to acquire gas-phase UV absorption spectra for [HS - H]^- and [OS - H]^-via photodepletion from 3.0-5.8 eV. No photofragmentation (i.e. dissociation of the ionic molecular framework) was observed for either [HS - H]^- and [OS - H]^- following photoexcitation, revealing that electron loss entirely dominates the electronic decay pathways for these systems. High-level quantum chemical calculations were used to map out the excited states associated with [HS - H]^- and [OS - H]^-, revealing that the minimum-energy crossing points (MECPs) between the S₁ and S₀ states are located in elevated regions of the potential energy surface, making internal conversion unlikely. These results are consistent with our experimental observation that electron detachment out-competes hot ground state molecular fragmentation. More generally, our results reveal that the competition between molecular dissociation and electron detachment following anion photoexcitation can be determined by the magnitude of the energy gap between the excitation energy and the MECPs, rather than being a simple function of whether the excitation energy lies above the anion's vertical detachment energy.

Effects of Structure on the Solubility of UV Filters

In recent years, one of the most concerning topics in healthcare is the constant exposure to ultraviolet (UV) light being the cause of numerous skin diseases. This issue created a keen interest in sun-care cosmetics, and particularly in sunscreens, since it has been proven to significantly reduce human skin disorders. Usually, sunscreens are formulated as emulsions with organic UV-absorbers dissolved in the oil phase; thus, the solubility of these UV-filters in the emollients is crucial. In this work we expose the properties of different emollients, correlating the chemical structure with the ability to dissolve organic UV-filters.

In Vitro Assessment of Sunscreen Efficacy Using Fourier Transform Infrared (FTIR) Spectroscopy on Synthetic Skin

Although there are several methods for assessing the sun protection factor (SPF) of sunscreen products, there is no standard and reliable in vitro method. Each test entails limitations and drawbacks. Therefore, this study aimed to assess the employability of FTIR as an alternative and quick method to evaluate the efficacy of various sunscreen formulations, their concentrations, and the timing of their application. Infrared radiation has longer wavelengths than ultraviolet, penetrates deeply into the skin, and hence enables the understanding of sunscreens' ability to block the transmission of radiation. The FTIR transmission using synthetic skin to study the effect of sunscreen agents (oxybenzone, octyl methoxycinnamate, titanium dioxide (TiO₂), and zinc oxide (ZnO)) was conducted in the range 450-4000cm^-1. Comparison studies were made at the peak of 805cm^-1. After 2 h of sunscreen application, using the maximum concentrations, the FTIR peak at wavenumber 805cm^-1 demonstrated a significant reduction of transmission from 96.55 to 60.09%, 57.59%, 32.02%, and 37.1% for oxybenzone, octyl methoxycinnamate, TiO₂, and ZnO respectively (P<0.05). A significant reduction in transmission was observed (P<0.05) with increasing sunscreen concentrations after 2 h of application. Nevertheless, the upper limit of concentration showed no appreciable change from the middle level of concentration, and hence it is cost-effective to employ the middle concentration. Inorganic sunscreens showed a higher protection level than organic. Fixed-dose combinations of sunscreens showed an enhanced effect yet were not synergistic. In conclusion, the use of FTIR spectroscopy with synthetic skin is a quick and user-friendly technique that enables the assessment of the efficacy of sunscreen formulations.

Silsesquioxanes in the Cosmetics Industry-Applications and Perspectives

The rising demand for innovative and sophisticated personal care products is a driving factor for manufacturers to obtain new formulations that will fulfill the customers' preferences. In recent years, silsesquioxanes have attracted the attention of the cosmetics industry. These compounds have been proposed to be used in novel cosmetic formulations as emollient, dispersant, and viscosity modifiers. Therefore, this publication aims to review the main important aspects of polyhedral oligosilsesquioxanes as ingredients of personal care formulations, taking into consideration different types of products. The methods of obtaining these compounds were also presented. Additionally, the detailed analysis of patents dedicated to the application of silsesquioxanes in cosmetic formulations was also performed.

Elucidating the Size-dependent FRET Efficiency in Interfacially Engineered Quantum Dots attached PBSA Sunscreen

Applying sunscreen on human skin provides photoprotection against the harmful ultraviolet (UV) radiation of the sun. Sunscreen absorbs UV radiations and dissipates the absorbed energy through various radiative and non-radiative pathways. The attachment of functionalized quantum dots (QDs) to the sunscreen component is a novel idea to enhance the absorption cross-section of UV radiations. Therefore, the attachment of the sunscreen component to the ligand functionalized biocompatible QDs and the absorbed energy transfer from sunscreen to the QDs could work as a model system to overall improve the efficiency of the sunscreen. This study elucidates the mechanism of size-dependent Förster resonance energy transfer (FRET) efficiency and its rate between 2-phenylbenzimidazole-5-sulfonic acid (PBSA) and mercaptoacetic acid (MAA) functionalized CdS QDs. In the PBSA-QDs dyad, the PBSA (donor) dissipates UV-absorbed energy to the CdS QDs (acceptor). Following excitation at 306 nm, the steady-state photoluminescence (SSPL) and time-resolved photoluminescence (TRPL) techniques measurements demonstrate that both the non-radiative energy transfer efficiency and rate are QDs size-dependent in addition to donor-acceptor distance, and suggest that bigger sized-QDs result in an increase of the FRET efficiency.

Substituted Tetraethynylethylene-Tetravinylethylene Hybrids

A general synthetic approach to molecular structures that are hybrids of tetraethynylethylene (TEE) and tetravinylethylene (TVE) is reported. The synthesis permits the controlled preparation of many previously inaccessible structures, including examples with different substituents on each of the four branching arms. Most substituted TVE-TEE hybrids are found to be significantly more robust compounds than their unsubstituted counterparts, enhancing the prospects of their deployment in conducting materials and devices. Their participation in pericyclic reaction cascades, leading to sp³-rich polycycles, is demonstrated. The utilization of TEE-TVE hybrids as building blocks for larger acyclic, through/cross-conjugated hydrocarbon frameworks is also established. Aryl-substituted TEEs, TVEs, and their hybrids are fluorescent, with some exhibiting aggregation-induced emission enhancement. The structural requirements are defined and explained, setting the scene for applications as fluorescent probes and organic light-emitting diodes.

Anti-Photoaging and Anti-Inflammatory Effects of Ginsenoside Rk3 During Exposure to UV Irradiation

Ginseng is a widely cultivated perennial plant in China and Korea. Ginsenoside Rk3 is one of the major active components of ginseng and is a promising candidate to regulate skin pigments and exert anti-photoaging effects on skin physiology. Ginsenoside Rk3 was mixed with a cream (G-Rk3 cream) and smeared on the skin of mice. Then, the mice were exposed to ultraviolet (UV) A (340 nm and 40 W) and UVB (313 nm and 40 W) radiation. Special attention was given to the anti-photoaging and anti-inflammatory effects of ginsenoside Rk3 on the mouse skin. Macroscopic evaluation indicated that the mouse dorsal skin looked smooth and plump even under UV irradiation for 12 weeks. Pathological analysis indicated that there was no obvious photoaging or inflammation in the mouse skin that was treated with the G-Rk3 cream. More healthy, intact, and neat collagen fibers were observed in mice treated with the G-Rk3 cream than in untreated mice. Further analysis proved that ginsenoside Rk3 could inhibit the decrease in water and hydroxyproline levels in skin tissues and the loss of superoxide dismutase and glutathione peroxidase activities in the blood. Moreover, ginsenoside Rk3 slowed or halted increases in malondialdehyde, matrix metalloproteinase (MMP)-1, and MMP-3 levels in the blood and levels of interleukin 1, interleukin 6, and tumor necrosis factor α in skin tissues. In conclusion, ginsenoside Rk3 plays a significant role in inhibiting photoaging and inflammation to protect skin health.

Effects of substituent position on aminobenzoate relaxation pathways in solution

The negative effects of ultraviolet radiation (UVR) on human skin have led to the widespread use of sunscreens, i.e. skincare products containing UV filters to absorb, reflect or otherwise block UVR. The mechanisms by which UV filters dissipate energy following photoexcitation, i.e. their photodynamics, can crucially determine a molecule's performance as a sunscreen UV filter. In this work, we evaluate the effects of substituent position on the in-solution relaxation pathways of two derivates of methyl anthranilate (an ortho compound that is a precursor to the UV filter meradimate), meta- and para-methyl anthranilate, m-MA and p-MA, respectively. The photodynamics of m-MA were found to be sensitive to solvent polarity: its emission spectra show larger Stokes shifts with increasing polarity, and both the fluorescence quantum yield and lifetimes for m-MA increase in polar solvents. While the Stokes shifts for p-MA are much milder and more independent of solvent environment than those of m-MA, we find its fluorescence quantum yields to be sensitive not only to solvent polarity but to the hydrogen bonding character of the solvent. In both cases (m- and p-MA) we have found common computational methods to be insufficient to appropriately model the observed spectroscopic data, likely due to an inability to account for explicit solvent interactions, a known challenge in computational chemistry. Therefore, apart from providing insight into the photodynamics of anthranilate derivatives, the work presented here also provides a case study that may be of use to theoretical chemists looking to improve and develop explicit solvent computational methods.

Quality by design enabled the development of stable and effective oil-in-water emulsions at compounding pharmacy: the case of a sunscreen formulation

It is widely accepted that the use of topical sunscreens has medical importance with potential to prevent skin damage by protecting from solar ultraviolet radiation (UVR) effects. Pharmaceutical emulsions require an optimal qualitative and quantitative combination of emollients, emulsifiers and others compounds such as softening agents and, for sunscreens, a combination of chemical and physical UV filters. Herein, we applied the quality by design (QbD) concept to achieve stable and effective compounded sunscreen emulsions. By using the statistical tool of design of experiments, it was possible to identify the influence of emulsifier type (with low and high Hydrophile-Lipophile Balance) and concentrations of emollient and softening agent on the achievement of formulations with suitable organoleptic and physicochemical features. Compounded emulsions with pleasant macroscopic aspects were obtained. Three formulations with physicochemical properties in targeted ranges were selected, namely pH ∼6.0, conductivity > 0.0 µS/cm², spreadability factor ∼1-1.5 g/mm², viscosity ∼12000 mPa.s and sunscreen protection factor ∼30. Freeze-thaw cycle and accelerated stability study under different storage conditions allowed selecting a stable emulsion that ensured photoprotection in biological assays. The QbD approach was essential to select the best, low-cost compounded sunscreen emulsion, with targeted physicochemical parameters.

Diethyl sinapate-grafted cellulose nanocrystals as nature-inspired UV filters in cosmetic formulations

Inspired by nature’s photoprotection mechanisms, we report an effective UV-blocking nanomaterial based on diethyl sinapate-grafted cellulose nanocrystals (CNC-DES). The colloidal stability and UV-blocking performance of CNC-DES in aqueous glycerol (a common humectant in petroleum-free cosmetic formulations) and in a commercially available moisturizing cream were studied. Grafting the water-insoluble DES onto CNCs renders it dispersible in these water-based formulations, thanks to the excellent water-dispersibility of CNC nanoparticles. Glycerol dispersions containing 0.1 to 1.5 wt% CNC-DES display very high UV-blocking activity owing to the anti-UV DES moieties anchored onto CNCs. A facial cream blended with 1.5 wt% CNC-DES exhibits an SPF of 5.03, which is higher than a commercially available sunscreen with the same active ingredient concentration (SPF = 3.84). DPPH radical scavenging assay also showed the antioxidant potential of CNC-DES, albeit coinciding with a significant reduction in antioxidant activity after grafting DES onto CNCs. Cytotoxicity measurements revealed the CNC-DES not to cause significant cytotoxicity to murine fibroblast cells after 24 h of exposure. Overall, CNC-DES exhibits strong anti-UV and antioxidant properties and is water-dispersible, biocompatible, non-greasy, and lightweight. This study demonstrates the exceptional potential of DES-grafted CNCs as nature-inspired UV filters in the next generation of cosmetic formulations, including those for sensitive skins.

Reducing the prevalence of chemical UV filters from sunscreen in aquatic environments: Regulatory, public awareness, and other considerations

Given increasing concerns about the persistence and toxic effects of some sunscreen ingredients in aquatic ecosystems, several states, territories, and nations have banned the sale and/or possession of sunscreens containing chemicals of concern. Little is known, however, about the outcomes or effectiveness of these efforts to reduce the prevalence of toxic chemicals in coastal waters. This article reviews the state of knowledge relating to regulatory and other efforts to reduce the impact of chemical ingredients in sunscreens on aquatic ecosystems, focusing on the following questions: To what extent will local legislative restrictions on ingredients actually reduce the concentrations of chemicals in coastal waters and protect aquatic health? Do these legislative measures effectively decrease overall public use of sunscreens containing potentially harmful ingredients, or would other measures, such as local outreach programs, consumer education, or broad-scale ingredient regulation, be more effective? How might restrictions on chemical UV filters impact human health? Although it is still early to assess the outcomes of recent ingredient bans, their effectiveness is limited by the fact that legislation generally applies only to sunscreens sold within the legislating jurisdiction. Public awareness campaigns can be locally effective, but they are hindered by the absence of clear environmental labeling standards for sunscreen. Although retail and industry groups, and many dermatologists, cite concerns that sunscreen ingredient bans might lead to increased incidences of skin cancer, consumer preferences are influenced by a wide range of factors and no studies clearly document whether restrictions on chemical ingredients will cause people to use sun protection less frequently or less effectively. Until more information is available, many consider it prudent to take a precautionary approach to sunscreen regulation supported by broad-scale, consistent regulatory policies and labeling standards that limit chemical ingredients to those considered safe for human use and ecosystem health. Integr Environ Assess Manag 2021;17:982-988. © 2021 SETAC.

Zebrafish as a Useful Model to Study Oxidative Stress-Linked Disorders: Focus on Flavonoids

The zebrafish is considered one of the most versatile experimental animal models. The transparency of the embryos, the small size, the rapid development and the homology with higher vertebrates have made the zebrafish a valuable model also for drug screening. Its use is closely related for the determination of bioactivity, toxicity and off-target side effects of novel drug candidates, which also allows a thorough evaluation of new targets; thus, it may represent a suitable model for drug screening and the optimization of novel candidates. Flavonoids are polyphenolic compounds widely present in fruits, vegetables and cereals. Polyphenols are important for both plants and humans, considering their involvement in defense mechanisms, particularly against oxidative stress. They protect plants from biotic and abiotic stressors and prevent or treat oxidative-based human diseases. For these reasons, polyphenols are used as nutraceuticals, functional foods and supplements by the pharmaceutical industry. Therefore, the most relevant findings on zebrafish as a useful experimental model to study oxidative stress-linked disorders, focusing on the biological activities of flavonoids, are here summarized and reviewed.

Zn(ferulate)-LSH Systems as Multifunctional Filters

Excessive UV solar radiation exposure causes human health risks; therefore, the study of multifunctional filters is important to skin UV protective ability and also to other beneficial activities to the human organism, such as reduction of reactive oxygen species (ROS) responsible for cellular damages. Potential multifunctional filters were obtained by intercalating of ferulate anions into layered simple metal hydroxides (LSH) through anion exchange and precipitation at constant pH methods. Ultrasound treatment was used in order to investigate the structural changes in LSH-ferulate materials. Structural and spectroscopic analyses show the formation of layered materials composed by a mixture of LSH intercalated with ferulate anions, where carboxylate groups of ferulate species interact with LSH layers. UV-VIS absorption spectra and in vitro SPF measurements indicate that LSH-ferulate systems have UV shielding capacity, mainly UVB protection. The results of reactive species assays show the ability of layered compounds in capture DPPH^•, ABTS^•+, ROO^•, and HOCl/OCl⁻ reactive species. LSH-ferulate materials exhibit antioxidant activity and singular optical properties that enable their use as multifunctional filters.

A post-HF approach to the sunscreen octyl methoxycinnamate

Octyl methoxycinnamate (2-ethylhexyl 4-methoxycinnamate, OMC) is a commercial sunscreen known as octinoxate with excellent UVB filter properties. However, it is known to undergo a series of photodegradation processes that decrease its effectiveness as a UVB filter. In particular, the trans (E) form-which is considered so far as the most stable isomer-converts to the cis (Z) form under the effect of light. In this work, by using post-Hartree-Fock approaches [CCSD, CCSD(t), and CCSD + T(CCSD)] on ground state OMC geometries optimized at the MP2 level, we show that the cis and trans forms of the gas-phase OMC molecule have comparable stability. Test calculations on the same structures with a series of dispersion-corrected density functional theory-based approaches including the B2PLYP double hybrid predict the trans structures to be energetically favored, missing the subtle stabilization of cis-OMC. Our results suggest that the cis form is stabilized by intra-molecular dispersion interactions, leading to a folded more compact structure than the trans isomer.

Effects of UV-filter Photostabilizers in the Photostability and Phototoxicity of Vitamin A Palmitate Combined with Avobenzone and Octyl Methoxycinnamate

A challenge for cosmetic and dermatologic products is to develop new high-performance and safer anti-aging products based on new compounds to enhance the stability of retinyl palmitate combined with broad-spectrum UV-filters. Consequently, the aim of this work was to evaluate the effects of three often used avobenzone photostabilizers-ethylhexyl methoxycrylene (EHMCR), tris(tetramethylhydroxypiperidinol) citrate (TTMHP) and tris-biphenyl triazine (TBPT)-on the photostability and phototoxicity of the combination of avobenzone (AVO), octyl methoxycinnamate (OMC) and retinyl palmitate (RP). The photostability studies were performed by the exposure of formulations to UVA radiation. The phototoxicity was evaluated by the 3T3 neutral red uptake phototoxic assay (OECD TG 432). The addition of EHMCR, TBPT, and TTMHP in the formulations, with/or without RP, improved the photostability of AVO and RP, but EHMCR was the most effective in stabilizing RP. In the phototoxicity assay, the combinations AVO-OMC containing or not RP showed phototoxic potential. EHMCR and TTMHP reduced the phototoxicity of the combination AVO-OMC, whereas EHMCR also decreased the phototoxicity of the combination containing RP. Therefore, EHMCR might be used to the photostabilization of formulations of AVO-OMC with/or not RP, while TTMHP can be added to this photounstable UV-filter combination.

Sunscreens and their usefulness: have we made any progress in the last two decades?

Sunscreens have now been around for decades to mitigate the Sun's damaging ultraviolet (UV) radiation which, although essential for the existence of life, is a recognized prime carcinogen. Accordingly, have suncreams achieved their intended purposes towards protection against sunburns, skin photo-ageing and the like? Most importantly, however, have they provided the expected protection against skin cancers that current sunscreen products claim to do? In the last two decades, there have been tens, if not hundreds of studies on sunscreens with respect to skin protection against UVB (280‒320 nm)-traditionally sunscreens with rather low sun protection factors (SPF) were intended to protect against this type of radiation-and UVA (320‒400 nm) radiation; a distinction between SPF and UVA protection factor (UVA-PF) is made. Many of the studies of the last two decades have focused on protection against the more skin-penetrating UVA radiation. This non-exhaustive article reviews some of the important facets of what is currently known about sunscreens with regard (i) to the physical UV filters titanium dioxide (TiO₂) and zinc oxide (ZnO) and the mostly photo-unstable chemical UVB/UVA filters (e.g., octinoxate (OMC) and avobenzone (AVO), among others), (ii) to novel chemical sunscreen agents, (iii) to means that minimize the breakdown of chemical filters and improve their stability when exposed to UV sunlight, (iv) to SPF factors, and (v) to a short discussion on non-melanoma skin cancers and melanoma. Importantly, throughout the article we allude to the safety aspects of sunscreens and at the end ask the question: do active ingredients in sunscreen products pose a risk to human health, and what else can be done to enhance protection? Significant loss of skin protection from two well-known commercial suncreams when exposed to simulated UV sunlight. Cream I: titanium dioxide, ethylhexyl triazone, avobenzone, and octinoxate; Cream II: octyl salicylate, oxybenzone, avobenzone, and octinoxate.

Nano-Structured Lignin as Green Antioxidant and UV Shielding Ingredient for Sunscreen Applications

Green, biocompatible, and biodegradable antioxidants represent a milestone in cosmetic and cosmeceutical applications. Lignin is the most abundant polyphenol in nature, recovered as a low-cost waste from the pulp and paper industry and biorefinery. This polymer is characterized by beneficial physical and chemical properties which are improved at the nanoscale level due to the emergence of antioxidant and UV shielding activities. Here we review the use of lignin nanoparticles in cosmetic and cosmeceutical applications, focusing on sunscreen and antiaging formulations. Advances in the technology for the preparation of lignin nanoparticles are described highlighting structure activity relationships.

Preparation of Efficient Ultraviolet-Protective Transparent Coating by Using a Titanium-Containing Hybrid Oligomer

Ultraviolet (UV) radiation is closely related to people's lives, but excess UV exposure has led to a series of problems. UV protection technology plays a vital role in our life. The most commonly adopted UV protection technology is to use UV-absorbing materials to make protective coatings, including sunscreen cream for human skin and sunscreen coating for materials. Conventional organic UV-protective coatings have low stability and are sensitive to heat, while inorganic UV-protective coating with highly efficient UV-protective performance usually need high processing temperatures and exhibit low transparency. Here, we report a Ti-PEG-Si cross-linked inorganic-organic hybrid material, which exhibits good UV-absorbing performance. By using these UV-absorbing materials, an efficient transparent UV-absorbing coating could be easily prepared at room temperature (298 K). The UV-absorbing coating is mainly composed of titanium and silicon connected by PEG200. PEG200 as a cross-linker can improve the UV-absorption performance of the coating and increase its visible light transmittance. At the same time, the existence of PEG200 can effectively increase the stability and elasticity of the coating and maintain its mechanical properties after UV irradiation. Furthermore, the coating could maintain highly UV-protective performance and could be transparent even after thermal treatment at high temperature (973 K). From this point of view, the hybrid materials have considerable application potential in next-generation UV protective coatings, especially with their utilization in heat-sensitive substrates or under high-temperature conditions.

Ultraviolet filters in sunscreens and cosmetic products-A market survey

BACKGROUND

As several reports have raised a variety of environmental, health, and safety issues related to ultraviolet (UV) filters, it is crucial to understand the trends in the exposure of the population to UV filters.

OBJECTIVE

To determine the frequency of UV filter usage in sunscreens and other cosmetic products in Thai market.

METHODS

We surveyed the UV filter labelling on sunscreens and cosmetic products sold in the Thai market. In all, 312 sunscreens and 1350 other cosmetic products were investigated.

RESULTS

Titanium dioxide was the most frequently used UV filter in both sunscreens (66.7%) and other cosmetic products (68.4%). Ethylhexyl methoxycinnamate was the most common organic UVB filter, whereas butyl methoxydibenzoylmethane was the most common organic UVA filter. In sunscreens aimed at children, bis-ethylhexyloxyphenol methoxyphenyl triazine was the most commonly used UV filter. The most frequent co-occurrence of UV filters was titanium dioxide and ethylhexyl methoxycinnamate.

CONCLUSIONS

Titanium dioxide was the most commonly used UV filter, which differs from the findings of previous surveys. Knowing the availability and frequency of each UV filter provides valuable information about consumer exposure levels, facilitates refinements of the allergen series in patch testing, and enhances the monitoring of adverse effects of UV filters.

Ultraviolet light screen using cholesteric liquid crystal capsules on the basis of selective reflection

When the prepared cholesteric liquid crystal microcapsule is applied to the skin, it can protect the skin by selectively reflecting only ultraviolet rays in sunlight like sunscreen cosmetics.

Grafting Nature-Inspired and Bio-Based Phenolic Esters onto Cellulose Nanocrystals Gives Biomaterials with Photostable Anti-UV Properties

New nature-inspired and plant-derived p-hydroxycinnamate esters and p-hydroxycinnamate diesters provide excellent protection against UV radiation when incorporated into a matrix. Herein, an efficient and sustainable pathway is reported to graft these phenolic compounds onto cellulose nanocrystals (CNCs) via click-type copper-catalyzed azide/alkyne cycloaddition (CuAAC) reaction. The successful grafting of the phenolic esters on CNC surface was evidenced by a range of chemical analyses, and the degrees of substitution (DS) of the CNC were found to depend on the structure of the phenolic ester grafted. Moreover, aqueous suspensions of the phenolic ester-grafted CNCs not only strongly absorb in both the UVA and UVB regions, but they also exhibit average to very high photostability. Their wide spectrum UV-absorbing properties and their stability upon exposure to UV are highly influenced by the structure of the phenolic ester, particularly by the extra ester group in p-hydroxycinnamate diesters. These findings demonstrate that cellulose nanocrystals decorated with such plant-derived and nature-inspired phenolic esters are promising sustainable nanomaterials for anti-UV applications.

Bemotrizinol-Loaded Carnauba Wax-Based Nanostructured Lipid Carriers for Sunscreen: Optimization, Characterization, and In vitro Evaluation

Nanostructured lipid carriers (NLC) are aqueous dispersions of nanoparticles formed by solid and liquid lipids. In this study, NLC containing an organic UV filter, bemotrizinol, were developed for sunscreen formulation using carnauba wax and caprylic/capric triglycerides through ultrasonication technique. A Box-Behnken design was used to evaluate the influence of three variables on the particle size with the purpose of choosing the best system for further characterization. The particle size decreased as the surfactant concentration increased, reaching an average size of 122.4 ± 0.3 nm at 30 days of storage. Scanning electron microscopy showed intact and spherical particles. Thermal analysis and Fourier-transform infrared spectroscopy suggest that bemotrizinol was incorporated into the NLC. The X-ray diffraction showed a reduction in the crystallinity of the NLC. In vitro analysis indicated an improvement in the photoprotective activity of bemotrizinol when incorporated into NLC. These findings suggest a promising, stable, and biocompatible system.