Sunscreen Cosmetics Research Articles

New technologies in sunscreen cosmetics

The aim of the present experimental study is the incorporation of an extract of the Porphyra Umbilicalis seaweed, which contains mycosporin derivatives (MAAs) in a sunscreen formulation, in combination with organic filters, in order to study its influence on the SPF and UVA PF. The results obtained from the in vitro SPF and UVA PF measurements as well as the physicochemical stability control of the new formulas, contribute to the effort for the partial replacement of organic sunscreen filters in sunscreen compositions.

A Comparative Study of Cerium(III) and Cerium(IV) Phosphates for Sunscreens.

Crystalline cerium(III) phosphate (CePO4), cerium(IV) phosphates, and nanocrystalline ceria are considered to be promising components of sunscreen cosmetics. This paper reports on a study in which, for the first time, a quantitative comparative analysis was performed of the UV-shielding properties of CePO4, Ce(PO4)(HPO4)0.5(H2O)0.5, and CePO4/CeO2 composites. Both the sun protection factor and protection factor against UV-A radiation of the materials were determined. Ce(PO4)(HPO4)0.5(H2O)0.5 was shown to have a sun protection factor of 2.9, which is comparable with that of nanocrystalline ceria and three times higher than the sun protection factor of CePO4. Composites containing both cerium dioxide and CePO4 demonstrated higher sun protection factors (up to 1.8) than individual CePO4. When compared with the TiO2 Aeroxide P25 reference sample, cerium(III) and cerium(IV) phosphates demonstrated negligible photocatalytic activity. A cytotoxicity analysis performed using two mammalian cell lines, hMSc and NCTC L929, showed that CePO4, Ce(PO4)(HPO4)0.5(H2O)0.5, and nanocrystalline ceria were all non-toxic. The results of this comparative study indicate that cerium(IV) phosphate Ce(PO4)(HPO4)0.5(H2O)0.5 is more advantageous for use in sunscreens than either cerium(III) phosphate or CePO4/CeO2 composites, due to its improved UV-shielding properties and low photocatalytic activity.

Concept for creating sunscreen cosmetics

Concept for creating sunscreen cosmetics

Concept for creating sunscreen cosmetics

Concept for creating sunscreen cosmetics

Synthesis of an AVB@ZnTi-LDH composite with synergistically enhance UV blocking activity and high stability for potential application in sunscreen formulations

1-(4-(1,1-Dimethylethyl)phenyl)-3-(4-methoxyphenyl)-1,3-propanedione (known as Avobenzone/AVB), widely used throughout the world as a highly effective UVA absorber, can prevent the progression of photoaging in skin, and is also known for the disadvantage of having a reduced capability to absorb UVA when exposed to sunlight for long periods. To address this challenge, ZnTi-CO3-LDH with a two-dimensional layered structure was used to improve stability and synergistically enhance UV absorption of AVB. A novel AVB loaded ZnTi-CO3-LDH (AVB@ZnTi-LDH) material was synthesized by reconstruction method and the loading content (LC) was about 46.8% investigated by high-performance liquid chromatography (HPLC). A possible mechanism for the binding of AVB with the ZnTi-LDH surface was proposed. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations were used to confirm further the coordination between Zn on the layer and the oxygen atom of the carbonyl group of AVB. UV absorption and critical wavelength of AVB@ZnTi-LDH were superior to those of AVB and ZnTi-LDH precursors. Compared with pure AVB, the photodegradation rate was reduced from 15.06% to 4.06%. Especially in titanium dioxide, the decomposition rate was reduced from 29.75% to 7.92%. Furthermore, pure AVB often reacts with multivalent metal ions to induce an unpleasant color (light yellow to reddish brown), which is greatly mitigated with AVB@ZnTi-LDH. In this study, avobenzone was combined with hydrotalcite to prepare an organic-inorganic composite with excellent UV resistance and better stability, the composite has great promise for application in sunscreen cosmetics.

Research on Permeation Influencing Factors of Cosmetics UV Filters and Improve In Vitro Permeation Tests (IVPTs)

The ideal UV absorber should be safe and should have excellent properties. Therefore, transdermal absorption is essential for the safety risk assessment of sunscreen cosmetics. The Franz diffusion cell method is the most common means of studying in vitro penetration, but there is a lack of standard methods for the in vitro permeation of UV absorbers. This paper used the Franz diffusion cell method to improve an in vitro permeation test (IVPT) for UV absorbers; three commonly used UV absorbers were tested: Octinoxate (EHM), Diethylaminohydroxybenzoyl hexyl benzoate (DHHB), and Ensulizole (PBSA). The final parameters were as follows: porcine ear skin was chosen for the membrane; the temperature of the receptor fluid was 37 °C; a PBS solution with 50% ethanol was chosen for the receptor fluid; and the dose of the test substance was 3 g. The improved IVPT method will help to accurately quantify the in vitro permeation of difficult-to-permeate components. In addition, the method can also be applied to evaluate the permeability of UV absorbers under different formulation conditions, which will help to address the difficulties related to the safety and application of sunscreen products.

A Novel Characteristic of a Water-soluble UV-B Absorber, 2-Phenylbenzimidazole-5-sulfonic Acid: Suppression of Riboflavin-sensitized Singlet Oxygen Generation

Abstract 2-Phenylbenzimidazole-5-sulfonic acid (PBSA) is a water-soluble UV-B absorber used in cosmetic sunscreens. Riboflavin (RF) is a water-soluble vitamin B2. RF is an efficient singlet oxygen photosensitizer. The effects of PBSA on RF-photosensitized singlet oxygen generation have been studied through measurements of transient absorption and time-resolved near-IR phosphorescence in phosphate buffer (pH 7.4). PBSA suppresses the RF-photosensitized singlet oxygen generation. The observed suppression can be ascribed to the quenching of the lowest excited triplet state of RF by PBSA.

Encapsulation of α-Lipoic Acid in Halloysite Nanotubes

A nanocomposite material based on halloysite and α-lipoic acid was studied. The kinetics of the degradation process of α-lipoic acid under the influence of ultraviolet radiation and thermal stress in its native state and in the composition of a halloysite-based nanocomposite were studied. The concentration of undegraded α-lipoic acid and the effect of the nanocomposite composition were determined by the HPLC method. It has been shown that adding α-lipoic acid to halloysite using a vacuum method allows for an increase in its resistance toward UV light of 84.4%, and the thermal resistance was also significantly improved. The composite based on halloysite and α-lipoic acid can be used to improve the resistance to photodegradation of pharmaceutical drugs or sunscreen cosmetics because this strategy preserves the biological active properties and shelf life of the α-lipoic acid.

The topical application of different galenic formulations can alter the thermographic images of skin: Limitations for public thermal screening on infection control situations

To analyze whether the application of topical formulas as cosmetics or sunscreens could affect the skin thermographic readings in terms of infection control in pandemic situations. The temperature of the skin of the dorsal region of the back and the face of 20 volunteers was followed after the application of 6 different types of gels, sunscreens, and make-up under controlled temperature and humidity conditions. High-resolution thermographic images were analyzed to calculate the temperature of treated skin compared to skin free of topical products. The application of hydroalcoholic gel resulted in a mean drop of more than 2°C just after 1minute followed by organic sunscreens until 1.7°C. Recovery was observed progressively until minute 9. Color make-up type formulas, rich in iron oxide as well as sunscreens with mineral filters had little or no effect on the skin thermal response. It is possible to alter the skin temperature almost immediately by using hydroalcoholic gels and sunscreen cosmetics. So, it is possible to produce false negative data in the readings of patients screened thermically.

Ultrafast excited-state energy dissipation pathway of diethylamino hydroxybenzoyl hexyl benzoate (DHHB) via the nanoparticles.

The organic UVA filter is popularized in sunscreen cosmetics due to the advantages of excellent light stability and high molar extinction coefficient. However, the poor water solubility of organic UV filters has been a common problem. Given that nanoparticles (NPs) can significantly improve the water solubility of organic chemicals. Meanwhile, the excited-state relaxation pathways of NPs might differ from their solution. Here, the NPs of diethylamino hydroxybenzoyl hexyl benzoate (DHHB), a popular organic UVA filter, were prepared by an advanced ultrasonic micro-flow reactor. The surfactant (sodium dodecyl sulfate) was selected as an effective stabilizer to prevent the self-aggregation of the NPs for DHHB. Femtosecond transient ultrafast spectroscopy (fs-TA) and theoretical calculations were utilized to trace and explain the excited-state evolution of DHHB in NPs suspension and its solution. The results reveal that the surfactant-stabilized NPs of DHHB reserve a similarly good performance of ultrafast excited-state relaxation. The stability characterization experiments demonstrate that the strategy of surfactant-stabilized NPs for sunscreen chemicals can maintain its stability and enhance the water solubility of DHHB compared with that of the solution phase. Therefore, the surfactant-stabilized NPs of organic UV filters are an effective method to improve water solubility and keep the stability from aggregation and photoexcitation.

1150 An ex vivo skin explant based scientific model to test the photoprotection efficacy of a cosmetic sunscreen product under controlled UV exposure

1150 An ex vivo skin explant based scientific model to test the photoprotection efficacy of a cosmetic sunscreen product under controlled UV exposure

Development of Unique Technology Using Plasma on a Liquid Surface, and Its Application to Novel Cosmetic Materials

Titanium dioxide (TiO2) nanoparticles have been used as ultraviolet light scattering agents in sunscreen cosmetics. However, they tend to self-aggregate due to their high surface energies and strong interparticle attraction in water. In this research, we focused on liquid surface plasma (LSP), and studied the water dispersion technology of fine-particle TiO2. The plasma formed is considered to generate shock waves and species such as O radicals, which have high oxidation potential, around the liquid surface. The LSP treatment enabled preparation of the aqueous dispersions with 10% (wt) TiO2 nanoparticles that have approximately 100 nm particle size and long-term stability. In addition, from the chemical analyses of the dispersions, Al compounds derived from the underwater Al electrode were formed on the TiO2 surface. It was clear that TiO2 nanoparticles had high positive charge under pH neutral condition due to Al compounds on the surface, so that the dispersions were stabilized by electrostatic repulsion between the particles. Furthermore, from the X-ray absorption fine structure (XAFS) measurements, it was found that the chemical state and molecular structure of Ti were not altered by the LSP treatment, and amorphous aluminum hydroxide (Al(OH)3) was detected on the surface. These findings suggest that the TiO2 aqueous dispersion obtained by the LSP treatment can be safely applied to cosmetics. Finally, a composite powder (PLD-TiB), which is BaSO4 covered with TiO2, was obtained by electrostatic combination in aqueous dispersion. From the SEM image, it was observed that the BaSO4 surface was uniformly coated with TiO2. Due to the uniform coating without aggregation, PLD-TiB had a great UV protecting effect and a smooth feeling on the skin.

Characterization, UV-induction, antioxidant function and role in photo-protection of mycosporine-like amino acids (MAAs) in a unicellular cyanobacterium, Euhalothece sp.WR7

Mycosporine-like amino acids (MAAs) are considered an important and unique UV-absorbing biomolecules. The present study was intended to explore the occurrence, UV-induction, free radical scavenging potential and photoprotective function of MAAs in the cyanobacterium, Euhalothece sp.WR7. High-performance liquid chromatography (HPLC) coupled with photodiode-array (PDA) detection studies revealed the occurrence of two different UV-absorbing compounds having absorption maxima at 331 nm and 362 nm with retention time 6.4 and 10.2 min, respectively. Based on the HPLC-PDA detection and ion trap liquid chromatography-mass spectrometry (LC-MS) analysis, the compounds were identified as mycosporine-2-Glycine (M2G: λmax 331 nm, m/z 303) and Euhalothece-362 (E-362: λmax 362 nm, m/z 331). Compared to the photosynthetically active radiation, a substantial induction of the synthesis of both MAAs was observed under UV (UV-A + UV-B) stress condition. MAAs (M2G + E-362) showed significant free radical scavenging potential in a dose-dependent manner. It also exhibited efficient photoprotective function by diminishing the UV-induced generation of reactive oxygen species (ROS) and enhancing the survival of Escherichia coli cells under UV-B stress. The results indicate the dynamic role of MAAs in existence and viability of cyanobacterium by regulating the key ecological functions in a harsh environment with intense solar UV irradiances. Moreover, MAAs may be used as important UV absorbers in cosmetic sunscreens due to their strong photoprotective function.

Dispersive liquid-liquid microextraction and Monte Carlo simulation of margin of safety for octocrylene, EHMC, 2ES, and homosalate in sunscreens.

Dispersive liquid-liquid microextraction (DLLME) using a floating organic drop has been optimized and used for the sample preparation of four commonly used ultraviolet filter (UVF) substances in sunscreens. Plackett-Burman experimental design was used to screen 10 variables in DLLME. The most significant variables were then optimized by using a response surface method with a Box-Behnken design. DLLME followed by an optimized HPLC identified octocrylene, 2-ethylhexyl-4-methoxycinnamate, ethylhexyl salicylate, and homosalate as the frequently found UVFs in commercial sunscreens. The systemic exposure dosage and margin of safety (MoS) for the identified UVFs were estimated using in-use concentrations and application patterns. The average systemic exposure dosage values for octocrylene, 2-ethylhexyl-4-methoxycinnamate, ethylhexyl salicylate, and homosalate were 0.52, 0.61, 0.020, and 0.079 mg/kg body weight per day, respectively. Whereas the average MoS values for individual UVFs ranging from 296 to 3160 were all significantly higher than the limit value of 100, the combined exposure risks were slightly above the limit. The probabilistic health risk assessment using Monte Carlo simulation revealed that the combined MoS values were (mean, 10‰, 90‰) 342, 119, and 441, respectively. Regarding the usage of sunscreen cosmetics containing the UVFs studied, these results indicate a safety concern for those who apply multiple UVF products.

Enhancing the FRET by tuning the bandgap of acceptor ternary ZnCdS quantum dots.

In this article, we report the band gap tuning of ternary ZnCdS quantum dots (QDs) by varying the concentration of the capping ligand, mercaptoacetic acid (MAA). The functionalization of QDs leads to the control of their size and band gap due to the quantum confinement effect, causing blue shift in the absorption and photoluminescence (PL) spectra with a gradual change in the concentration of the capping ligand from 0.5 to 2.5 M. Ensulizole (2-phenylbenzimidazole-5-sulfonic acid) is an important organic ultraviolet (UV) filter that is frequently used in sunscreen cosmetics. An effective overlapping of the PL spectrum of ensulizole and the absorption spectrum of QDs with 2.5 M MAA is achieved. A formidable decrease in the PL intensity and the PL lifetime of ensulizole promotes an efficient Förster resonance energy transfer (FRET) from sunscreen ensulizole to the QDs. The magnitude of the FRET efficiency (E) is ∼70%. This very high value of E is the signature of the existence of a very fast energy transfer process from ensulizole to the MAA functionalized ZnCdS QDs. The dyad system consisting of ZnCdS QDs and ensulizole sunscreen can serve as a prototype model to develop a better understanding of the photochemistry of ensulizole and consequently the formulation of more efficient sunscreen cosmetics.

Sunscreen cosmetics as basic protection against photoaging

The natural protective mechanisms of the skin indicate the harmful effects of sunlight, by the appearance of erythema and increased sweat secretion. The extremely unfavourable influence of solar radiation on the skin is the phenomenon of immunosuppression, which can lead to the formation of skin cancer foci. Effective sun protection delays skin photoaging, prevents sunburn and the formation of cancer. The available sun-protective preparations show increasing photostability. The aim of the work was to present fundamental issues in the field of sun protection and to explain the essence of the natural protective mechanisms of human skin. The article also explains the classification of sunscreen filters, divided into mineral (physical) and chemical ones.

In vitro and In vivo Evaluation of Sunscreen Formulations Containing Nanolipid Carriers

Abstract: The majority of sunscreen cosmetics are emulsions or creams. However, formulations that use lipid nanoparticles as the delivery vehicle for sunscreen chemicals may offer benefits in terms of skin retention, enhancement of penetration through the epidermal layer, and Ultraviolet (UV) absorption and scattering. Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have been investigated to create sunscreen products with low or medium UV protection. SLN and NLC have a wide range of characteristics and have been proven to effectively control the entry of actives showing UV protection activity through the skin. They have no hazardous effects; therefore, they can be employed safely in dermatological and cosmetic preparations to obtain different traits. When utilized as vehicles for molecular sunscreens, lipid nanoparticles showed a synergistic impact of UV scattering. The ability to minimize the concentration of the molecular sunscreen, its potential adverse effects, and the expenses of formulating pricey sunscreens are all advantages derived from these studies. The review discusses some research on how lipid nanoparticles have been encapsulating sunscreen agents. Exposure to sunlight is a key element in the aetiology of the gradual undesired changes in the skin look and physiology caused by UV rays present in the sunshine; hence evaluating sunscreen activity is an essential aspect of the cosmetic business. The author will also address some of the in vitro and in vivo assessments of sunscreens.

Inhibitory Effect of Seawater Pearl Hydrolysate on UVA-Induced Photoaging of Human Skin Fibroblasts.

This study is an investigation into the inhibitory effect of seawater pearl hydrolysate (SPH) on the UVA-induced photoaging of human skin fibroblast (HSF) cells, and the mechanism thereof. HSF cells were cultured and irradiated with a UVA 0–50 J·cm−2 dose gradient. The cell inhibition rate was detected using the CCK8 method, and the half-inhibitory dose was determined. Based on this, the dose of UVA irradiation for the follow-up experiment was selected to establish a photoaging model of the HSF cells. The cells were divided into a normal (N) group, UVA-irradiated (UVA) group, SPH low dose (SPHL) group, SPH medium dose (SPHM) group, and SPH high dose (SPHH) group. The photoaging model of HSF cells was established by UVA irradiation in the UVA, SPHL, SPHM, and SPHH groups; the SPHL, SPHM, and SPHH groups were treated with SPH at concentrations of 50, 100, and 200 mg·L−1, respectively, at the same time. After 24 and 48 h of culture, the reactive oxygen species (ROS) level of the HSF cells was detected by flow cytometry, and the required culture time of the HSF cells for the follow-up experiment was selected. The malondialdehyde and glutathione contents, as well as the activities of the superoxide dismutase, catalase, and glutathione peroxidase in the HSF cells, were detected by biochemical methods. The levels of expression of MMP-1 and collagen I protein in HSF cells were detected by the western blot test, the extent of aging of HSF cells was detected by β-galactosidase staining, and the apoptosis level of HSF cells was detected by flow cytometry. The results show that SPH inhibits the UVA-induced photoaging of HSF cells in a dose-dependent manner within a certain concentration range, and the effect of a concentration of 200 mg·L–1 was the most significant. The mechanism is related to improving the antioxidant activity of photoaging HSF cells to eliminate excessive ROS. It can inhibit apoptosis, reduce the protein expression of MMP-1, and effectively control the degradation of collagen I protein in photoaging HSF cells. Therefore, SPH offers potential for use in sunscreen cosmetics.

The Potential of Natural Ingredients as Sunscreen: A Narrative Literature Review

Sunlight is an electromagnetic wave that plays a role in producing UV radiation. UV radiation is a major source of skin damage. The utilization of natural ingredients as active ingredients in sunscreen cosmetics is an alternative to chemicals that are also harmful to the skin. Several plants, including Brucea javanica (L.), Family Myrtaceae, Hippobroma Longiflora (L) G. Don, Kaempferia galanga L, and Eucheuma cottonii. Doty and Zea mays L. have the potential to be developed as a sunscreen.

Spectrophotometric Determination of Sun Screen Potential of Selected Medicinal Plants

Ultraviolet (UV) radiation emitted by sun has found to be a major cause to damage or alter structure and function of human skin. Various sunscreen cosmetics have been employed to protect the skin from these damaging effects. Many plant materials have shown the potential as sunscreen agent to protect the skin. Previous research revealed the potential of plant products such as fixed oil, volatile oil and plant extracts could be used for their sunscreen potential. In the present study some of selected medicinal plants Azadirachta indica, Ocimum sanctum, Centella asiatica and Hibiscus rosa sinensis have been evaluated for their sunscreen potential by spectrophotometric method. The In vitro method has been used for the study was rapid, convenient, safe and reliable and could be useful in preliminary evaluation of sun protective potential. The result of the study indicated all hydroalcoholic extract have sun protective potential and can be used in cosmetic as sunscreen agent. The comparative result indicated that Azadirachta indica hydroalcoholic extract has higher sun protection efficiency and Hibiscus rosa sinensis has lowest photo protection efficiency, The initial result may be useful in selection the plant for sunscreen effect while developing a cosmetic formulation.