Sunscreen Research Articles

Synthesis and Evaluation of a ZnO-Chitosan Adduct for Safe and Sustainable Enhanced Ultra-Violet (UV) Sunscreens Protection.

Chitosan (Ch), a natural polysaccharide, is known for its biocompatibility, biodegradability, and various beneficial properties, including antioxidant and antibacterial activities. The objective of this study is to investigate the functionalization of zinc oxide (ZnO) with chitosan to develop a novel ZnO@Ch adduct for use in cosmetic formulations, specifically as a sun protection agent. The functionalization was achieved through ionotropic gelation, which enhanced the stability and reduced the photocatalytic activity of ZnO, thereby improving its safety profile for skin applications. FTIR spectroscopy confirmed the successful functionalization, while TGA and DSC characterized the thermal properties and stability. The Zeta potential and particle size analyses demonstrated improved stability of ZnO@Ch across various pH levels compared to uncoated ZnO. The structure of the obtained adduct was also confirmed by SEM analysis. The ZnO@Ch adduct exhibited enhanced stability at neutral and slightly alkaline pH values, reduced photocatalytic activity compared to pure ZnO, and had lower cytotoxicity in 3T3 cells compared to pure ZnO, particularly at higher concentrations. The ZnO@Ch adduct provided a higher Sun Protection Factor (SPF) and UVA Protection Factor (UVA-PF) than pure ZnO, indicating enhanced UV protection. The adduct's ability to provide higher SPF at lower ZnO concentrations offers economic and environmental benefits, aligning with sustainable product design principles. Future studies will focus on optimizing the formulation and testing the efficacy and safety at higher concentrations to fully realize its potential as a natural, eco-friendly sunscreen ingredient.

Harnessing microbes as sun cream against high light stress.

Plants rely on solar energy for growth through photosynthesis, yet excessive light intensity can induce physiological damage. Despite the considerable harm, inadequate attention has been directed toward understanding how plant-associated microorganisms mitigate this stress, and the impact of high light intensity on plant microbial communities remains underexplored. Through this Viewpoint, we aim to highlight the potential of microbial communities to enhance plant resilience and understand how light stress can shape plant microbiome. A full understanding of these dynamics is essential to design strategies that take advantage of microbial assistance to plants under light stress and to effectively manage the impact of changing light conditions on plant-microbe interactions.

Hybrid Sunscreen for Albinistic Skin Types Augmented by Terminalia Sericea Mediated Silver Doped Zinc Oxide Nanoparticles, Efficacy and Safety Investigation

Albinism is a congenital hypopigmentation disorder characterized by errors in melanisation leading to the partial or complete absence of melanin, the skin’s primary defense against actinic damage. Actinic damage in albinism summarizes all solar induced consequences from freckles to fatal skin cancers. Of the 16 sunscreens approved by regulators, 14 chemical sunscreens were stripped of GRASE (Generally Recognizable as Safe and Effective) status in 2020 by the FDA though Over-the-Counter Monograph M020, the remaining 2 physical sunscreens (ZnO and TiO2) are unaesthetic, leaving unpleasant persistent white casts. The hunt for new, effective and safe sunscreen agents is on and photoprotective polyphenolics from tropical plants including Terminalia sericea, maybe the solution. This study aimed to develop and evaluate the efficacy and safety of a novel sunscreen for albinistic skin, utilizing Terminalia sericea-mediated silver-doped ZnO nanoparticles, so as to leverage the novel sun protection efficacy of aesthetic ZnO-NPs with the antibacterial effects of Ag-NPs as well as the photoprotective effects from T. Sericea polyphenolics. Our observations from the study confirm that T. Sericea possesses abundant polyphenolic compounds capable of mediating bio-reducing and capping of metallic nanoparticles. UV-Vis identified the nanostructures as Ag-ZnONPs, TEM confirmed their cubic and oblong agglomerated morphology. DLS estimated the nanostructures to be between 30 and 40nm. The sunscreen achieved a high SPF of 30, showed significant photoprotective properties, and demonstrated negligible skin sensitization in safety tests following OECD guidelines. It was therefore concluded that the biosynthesis of multifunctional Ag doped ZnONPs mediated by T. Sericea, was feasible and that the resultant safe multifunctional emulsion was efficacious in retarding biomarkers of actinic damage and is a potential pioneering albinistic skin type actinic damage retarding sunscreen.

Sun exposure and challenges of sun protection in adolescents and young adults: A prevalence observational study.

The present study aimed to explore the adherence to and efficiency of skin protection measures among teenagers and young adults. The present study investigated the reasons for sun exposure and the obstacles impeding sun protection. In the summer of 2023, a self-reported questionnaire was posted on the social media account of two high schools, a university, some industrial companies and among the teenage children of a dermatology clinic. Descriptive statistics and multivariate logistic regression analyses were performed to assess the reasons for sun exposure behavior, sun protection measures and the frequency of sunburn among individuals aged 15 to 25 year. A total of 517 young individuals completed the questionnaire. It was found that 43.5% use a hat as a means of sun protection, and only 10% try to limit their exposure to the sun. Nevertheless, 78.7% indicate the use of sun cream, 61.7% expose themselves frequently or very frequently to the sun, and 51.2% exposed themselves to the sun for tanning. Young females were statistically more prone to tan [odds ratio (OR), 2.95; 95% confidence interval (CI), 1.95-4.46] P=0.03 than males. Males exposed themselves to a 3-fold greater extent during recreational activities (OR, 2.98; 95% CI, 1.56-5.69) P=0,025, compared to females. On the whole, the present study demonstrates that young individuals aged 15 to 25 years are exposing themselves too frequently to the sun. A large proportion of individuals still wishes to acquire a tan. Even if the large majority of individuals uses sunscreen, the majority of these do not protect themselves correctly since they report becoming sunburnt frequently.

Quantifying the sediment sorption of organic ultraviolet filter chemicals using solvophobic theory

Hydrophobic organic chemicals (HOCs) that enter the aquatic environment often negatively impact organisms, endangering aquatic biodiversity. Understanding sediment sorption equilibria for these chemicals can properly direct mitigation efforts. In addition, many HOCs of environmental concern lack sufficient environmental fate data to adequately assess their risk to ecosystems and humans. In this study, a sorption method addressing solvophobic effects was used to quantify the sorption of an HOC of current environmental concern, OD-PABA (padimate O, 2-ethylhexyl-4-(dimethylamino)benzoate), to a variety of sediments. OD-PABA is an organic ultraviolet filter chemical used in commercial sun protection products; it has been shown to exhibit cytotoxic effects and is known to photochemically transform under natural sunlight conditions. Given its commercial use, it enters the aquatic environment via recreational use and wastewater treatment plant effluent. OD-PABA is strongly hydrophobic; to mitigate the adsorption of OD-PABA to the container walls during sorption experiments, a precise concentration of methanol was used to avoid solvophobic effects. This sorption method was used to determine the sorption capacities for OD-PABA of four sediment samples, each with unique geochemical characteristics. Sediment-water distribution coefficients (Kd) were quantified and were normalized to various sediment characteristics to assess the main driving force(s) for sorption of OD-PABA. Organic carbon content was found to be a main driving force, with organic carbon-normalized distribution coefficients (log Koc) ranging from 4.4 to 4.6 for sediments with total organic carbon (TOC) > 10%); the clay fraction was also found to be important, especially for sediments with low TOC. The sorption of para-aminobenzoic acid (PABA), a water-soluble analog of OD-PABA was also investigated to assess the experimental approach, yielding a log Koc of 2.1 for the sediment with the greatest TOC.

The Potential of Clove (Syzygium aromaticum) Essential Oil as Sunscreen and Anti-Aging Agents: An In Vitro and In Silico Study

The earth thermal conditions increase exposure to sunlight, triggering skin damage. The skin has defense mechanisms but needs additional protection to prevent photoaging. Using sunscreen is an effort to reduce the harmful effects of sun exposure. Natural ingredients with antioxidant activity can be developed into sunscreen and antiaging products, including cloves. This study aims to assess the antioxidant, sun protection, and anti-aging properties of essential oils derived from clove leaves and buds. The antioxidant activity was assessed by the DPPH system and then formulated into 5 and 10 % clove leaves cream, as well as 5 and 10 % clove bud cream. The SPF values were assessed using a spectrophotometer and the Mansur formula. The antiaging potential was assessed using the in silico method with MMP-1 protein employing the Auto Dock Vina software, followed by analysis and visualization using BIOVIA Discovery Studio. The essential oils from clove leaves and buds have DPPH IC50 values of 23.09 and 30.31 ppm. The SPF values of clove leaves essential oil, 5 % leaves cream, and 10 % leaves cream are 38.61, 14.32, and 22.15. Meanwhile, the SPF values of clove bud essential oil, 5 % bud cream, and 10 % bud cream are 38.19, 9.32, and 18.16. The in silico test revealed that caryophyllene, eugenol, humulene, and phenol, 2-methoxy-4-(2-propenyl), acetate) have strong interactions because they can interact with the active site of proteins using hydrogen, hydrophobic, and van der Waals bonds. The essential oils from clove leaves and buds exhibit very strong antioxidant activity and offer ultra-protection as a sunscreen. The cream formulations still exhibit sunscreen activity, albeit at a lower level compared to pure essential oil. Caryophyllene, eugenol, humulene, and phenol, 2-methoxy-4-(2-propenyl)-, acetate), have potential as antiaging agents, as indicated by their binding affinity and chemical bond interactions observed in the in silico test. HIGHLIGHTS Clove buds and leaves exhibit antioxidant properties. Essential oil from clove buds and leaves demonstrates a substantial Sun Protection Factor (SPF). The compounds contained in clove essential oil exhibit promise as prospective agents in anti-aging applications. GRAPHICAL ABSTRACT

Formulation of Lotion with Ethanol Extract of Curcuma manga Val. as UV B Sunscreen and Activity Test using UV-Vis Spectrophotometry

Temu mango (Curcuma manga Val) is a rhizome plant native to Indonesia that contains curcuminoid and flavonoid antioxidant compounds. These compounds are thought to have activity as UV light protectors, especially UV B. This study uses a qualitative test of the compound content in temu mango followed by formulation and activity testing of water in oil (w/o) sunscreen lotion of temu mango in vitro. Optimization of w/o lotion formulation uses Design Expert® (DE) software version 9.0.4.1 with the Simplex Lattice Design method. The DE software obtained 13 runs of w/o lotion formula and continued with physical properties evaluation to determine the optimum formula. The optimum formula of lotion w/o predicted by DE software was tested for physical stability for four weeks, SPF test, percent pigmentation, and percent erythema using UV-Vis spectrophotometry. The results of the study show that temu mango extract was found to provide an SPF value at a concentration of 0.3 mg/mL with an SPF value of 16.62. The results of the optimum formula of lotion w/o were 7%glycerin, 7% cera alba, 5% cetyl alcohol with a value of stickiness of 0.70 ± 0.03 seconds, spreadability of 13.20 ± 0.83 cm2, and viscosity of 95.19 ± 3.06 dPa.s. Referring to the storage results, the optimum formula of w/o lotion from temu mango extract was stable during one month of storage. The w/o lotion in the optimum formula produced an SPF value of 15.06 ± 0.39, percent erythema of 10.95%, and percent pigmentation of 10.41%.

Sustainable design and synthesis of high-performance lignin-based sunscreen ingredients

The active ingredients most commonly employed in sunscreens are compounds containing one or two aromatic rings. Lignin is the most abundant renewable aromatic polymer that has the potential to yield low molecular weight aromatic chemicals when strategically depolymerized. Here, the UV absorbance of a series of monomeric and dimeric lignin model compounds (LMCs) were studied. Specifically, vanillin and ferulic acid demonstrated good absorption in the UVB (280–320 nm) range, while the 5–5 dimer showed efficient absorption in the UVA (320–400 nm) range. Based on this, vanillin, ferulic acid and 5–5 dimer were mixed in pairs and dispersed in the oily isoeugenol to prepare LMC hybrid dispersions. Subsequently, demethylated lignin (DL) was synthesized and used to encapsulate the LMC hybrid dispersions via ultrasonic cavitation to prepare DL-based nano-capsules (DLNCs). The DLNCs were used as the only active ingredient in sunscreens, whose sun protection factor (SPF) value could be up to 55 with a dosage of 10 wt%. Due to anti-photolysis property of DL, the SPF value of DLNCs-based sunscreens increased initially and maintained >8 h under UV irradiation. Additionally, the prepared DLNCs exhibited excellent anti-permeability, antioxidant capacity and biocompatibility, making them a potential substitute for conventional petroleum-based sunscreen agents.

Synthesis, Characterization, and Optical Properties of Novel Heterocyclic Azo Dyes and Evaluation of Their Antioxidant Activity as an Active Sunscreen Agent

AbstractWe synthesized some novel isoxazole azo derivatives using conventional methods and studied their linear, non‐linear optical properties and antioxidant activity. UV‐Vis spectroscopy revealed absorption bands ranging from 310–470 nm for the obtained compounds. Compounds 3 c and 3 b, for example, showed a large redshift and solvatochromic behavior. NLO analysis results show that compounds exhibit a greater NLO response than the magnitude of urea done by the DFT method. The electrochemical properties of compounds are studied using cyclic voltammetry and results are used for calculation of HOMO and LUMO experimentally. The antioxidant activity of the synthesized azo dyes displayed that 3 c has excellent antioxidant activity with the highest percentage (71.54605 %) of radical inhibition as compared to reference standard Vit‐C. Molecular docking analysis shows that compounds have a strong binding affinity in the range of −7.0 to −4.6 kcal/mol compared to Vit‐C, which has a binding affinity of −3.6 kcal/mol. The sun protection factor performance was determined by UV‐Vis spectroscopy, and results show that compounds are most effective, exhibit a remarkable SPF value, and offer superior sun protection by absorbing UV rays.

Sunscreens prescribed to patients with skin of color and/or with melasma: A survey of 221 dermatologists and dermatology residents in Spain.

Dark-skinned individuals (DSI) present high rates of melasma and post-inflammatory hyperpigmentation. The use of sunscreens with mineral filters is essential for prevention and treatment. Our objective was to determine the preferences of dermatologists and dermatology residents in the prescription of sunscreens for DSI. An anonymous survey of attendees at an online photoprotection event held on March 31, 2022, in Spain. The survey was answered by 66.6% (221/332) of the attendees: 159 dermatologists (71.9%) and 62 dermatology residents (28.1%). Respondents reported recommending the use of sunscreen to a median of 80% of DSI [interquartile range (IQR), 50-90]. Physicians reported prescribing tinted sunscreens to a median percentage of 60% (IQR, 25-90) of DSI with acne; and to a median percentage of 90% (IQR, 58-99) of DSI with melasma. The most prescribed photoprotectors to DSI with melasma were organic broad-spectrum sunscreens with antioxidants: 102/220 (46.4%) and mineral broad-spectrum sunscreens (with iron oxides): 45/220 (20.4%). In DSI with melasma or other pigmentary disorders, the most preferred features of sunscreens were as follows: sun protection factor ≥ 30: 217/221 (98.2%), UVA protection: 214/221 (96.8%), color for camouflage: 150/220 (68.2%) and mineral filters such as titanium dioxide and zinc oxide: 151/220 (68.6%) or iron oxides: 131/220 (59.5%). Online survey, potential inclusion bias. Respondents reported to prescribe sunscreens to the majority of DSI, and tinted sunscreens for the majority of DSI with pigmentary disorders. However, the most frequently recommended sunscreens for DSI were organic broad-spectrum sunscreens with antioxidants.

Potential and Activities of the Sunscreen Lotion Preparation of Bawang Dayak (Eleutherine americana (Aubl.) Merr. by Ethanol Extract Fraction from East Boneo

Has conducted research Potential and Activities of the Sunscreen Lotion of Bawang Dayak (Eleutherine americana (Aubl.) Merr. by ethanol extract fraction from East Borneo. The purpose of the study was to determine the potency ann activity of the sunscreen ethanol extracts fraction of Bawang Dayak in the preparation of a lotion with the parameter measuring the percent transmission erythema (% Te) and pigmentation (% Tp) in vitro in the room temperature 27oC storage and accelerated temperature 40oC. Lotion dosage formulations using ethanol extracts fraction bawang Dayak with a concentration of 0.1% and 0.2%, and positive control is a trademark preparation Bless Sunscreen Lotion SPF 15®. Stages of research include the formulation and measurement of absorbance and value %Te) and %Tp at various storage temperatures with UV-Vis spectrophotometry at λ 292.5 to 372.5 nm. The analysis of research data using a program SPSS. The results showed that ethanol extract fraction concentration in lotion preparations of bawang Dayak 0.1% and 0.2% active as a sunscreen included in the category of sunblock. The extract fraction is active as a sunscreen and in the Sunbloc category, with the best concentration as a sunscreen being 0.2%, with its sunscreen potential not being significantly different from the control Sunscreen SPF 15® at the 5% level.

Photopatch testing: Clinical characteristics, test results, and final diagnoses from the North American Contact Dermatitis Group, 2009-2020.

Photoallergic contact dermatitis (PACD) is a delayed hypersensitivity reaction to allergens only in the presence of ultraviolet radiation in sunlight. Photopatch testing (PhotoPT) is necessary to confirm the diagnosis of PACD. There are few published studies of PhotoPT in North America. To summarise the results of patients photopatch tested by members of the North American Contact Dermatitis Group (NACDG), 2009-2020. Retrospective analysis of patient characteristics and PhotoPT results to 32 allergens on the NACDG Photopatch Test Series. Most of the 454 tested patients were female (70.3%), 21-60 years old (66.7%) and White (66.7%). There were a total of 119 positive photopatch tests. Sunscreen agents comprised 88.2% of those, with benzophenones responsible for over half of them. Final diagnoses included PACD in 17.2%, allergic contact dermatitis (ACD) in 44.5%, polymorphous light eruption (PMLE) in 18.9% and chronic actinic dermatitis (CAD) in 9.0% of patients. In 454 patients with suspected photosensitivity referred for photopatch testing in North America, approximately one-fifth had PACD. Sunscreen agents, especially benzophenones, were the most common photoallergens. Other common diagnoses included ACD, PMLE and CAD. Photopatch testing is an important tool for differentiating these conditions.

PORPHYRIA CUTANEA TARDA IN A PATIENT, TREATED WITH HAEMODIALYSIS AFTER A KIDNEY TRANSPLANT REJECTION REACTION: A CASE REPORT

Porphyrias are a group of inherited metabolic disorders of haem biosynthesis, involving a deficiency in the enzyme uroporphyrinogen decarboxylase. In this case report we present a case of a patient with porphyria cutanea tarda (PCT). A 40-year-old man on haemodialysis after a kidney transplant rejection reaction, complaining of skin changes, with a history of smoking and alcohol intake. Treated with Fusidic acid and Betamethasone cream, and erythropoietin. Porhyria cutanea tarda can be considered in patient who complains of skin changes. History of alcohol intake, smoking, high ferritin levels and increased hepatic markers can raise suspicion of disease. In patient with ESRD treatment with erythropoietin, SPF 50+ sun cream, Fusidic acid and Betamethasone can be effective.

INDIVIDUAL ARTICLE: NECOM 4: Algorithm Integrating Skincare for the Management of Immunotherapy-Related Cutaneous Adverse Events for Cancer Patients and Survivors.

In the Nordic European Countries, cancer is the leading cause of death. The last decade has brought revolutionizing cancer treatments including immune checkpoint inhibitors (ICIs). Patients on ICIs have a high risk of developing cutaneous immune-related adverse events. Treating these side effects is of high importance to improve patient's quality of life (QoL) and continue the anti-cancer treatment. The Nordic European Cutaneous Oncodermatology Management (NECOM) project develops tools to prevent and treat cancer therapy-related cutaneous adverse events (cAEs). The first 2 NECOM papers presented various cAEs and skincare regimens involving hygiene, moisturization, sun protection, and camouflage products for preventing and managing cAEs. The NECOM 3 practical algorithm was on the prevention and treatment of acute radiation dermatitis. This NECOM 4 practical algorithm is intended to prevent and manage cutaneous immunotherapy-related adverse events (cirAEs), improving cancer patients' QoL and outcomes. The NECOM advisors discussed the results of a systematic literature review and obtained consensus on the evidence and expert opinion-based practical algorithm for cirAEs to support all healthcare providers treating cancer patients in the Nordic European Countries. The algorithm starts with a simple skincare regimen of cleansing, moisturizing, and protection, followed by the exclusion of severe cutaneous adverse reactions, and then specific interventions to treat the most common cirAEs (pruritus, maculopapular eruption, eczematous eruption, psoriasis, lichenoid eruption, and bullous eruption). CirAEs are the most common side effects induced by ICIs and may lead to cancer treatment interruption or even discontinuation. Patient education on the prevention of cirAEs using a skincare regimen and treatment recommendations given in the NECOM 4 algorithm may help prevent and manage cirAEs and improve the QoL and outcome of patients receiving ICIs. J Drugs Dermatol. 2024;23:8(Suppl 2):s4-10.

FORMULATION OF RED BETEL LEAF EXTRACT LOTION (Piper crocatum Ruiz & Pav) AS SUNSCREEN

Betel leaf is a natural ingredient that people use as a traditional medicine. One of the ingredients found in red betel leaves is a phenolic compound in the form of flavonoids, a photoprotective substance that can be used as protection from UV radiation. Sunscreen is a cosmetic preparation that can protect the skin from UV radiation and reduce the amount of radiation harmful to the skin. This study aimed to formulate a lotion preparation from red betel leaf extract that has activity as a sunscreen. Red betel leaf (Piper crocatum Ruiz & Pav) was extracted using the maceration method. Preparation formulations were made with variations of red betel leaf ethanol extract in each formula, namely with concentrations of 0.04% (F1), 0.05% (F2), 0.06% (F3), and base control (F0). The activity of sunscreen lotion extract is based on the Sun Protection Factor (SPF) value using UV-VIS spectrophotometry at wavelengths of 290–320 nm using the Mansur equation. The results of the SPF value of the lotion are F1 of 13.48, F2 of 16.71, and F3 of 18.7. The evaluation of the lotion results obtained a light green lotion with M/A emulsion type that met the requirements, including homogeneity, pH, spreadability, viscosity, centrifugation test, and freeze and thaw test. Research results show that betel leaf extract lotion is physically stable and has a high SPF value, so it has the potential to be a sunscreen.

UV-absorption Capacity of Selected Crude and Functionalized Lignin for Use in Sunscreens

The most commonly used commercial sunscreen agents are aromatic compounds oxybenzone and octinoxate, as they offer a wide range of protection in the UV spectrum. However, oxybenzone has the highest rate of skin irritation, while octinoxate has poor photostability. Oxybenzone is also a genotoxicant and skeletal endocrine disruptor to corals. Appropriate, less toxic and preferentially biorenewable alternatives should be recommended. Lignin, an abundant byproduct of pulp and biorefinery industries, is expected to be an effective replacement for oxybenzone and octinoxate due to its aromatic structure, which, in synergy with a wide variety of functional groups, produces the absorption of energy in the entire UV region. Additionally, lignin is a biocompatible polyphenolic with a strong radical quenching ability, i.e., anti-oxidizing potential. Therefore, it is a promising replacement for synthetic chemicals in cosmetics, sunscreen, and other applications. The UV absorption analysis of selected crude and functionalized lignin samples was conducted, and the results were compared to those of commercially used UV-absorption agents—oxybenzone and octinoxate. The results showed that the total absorption capacity of the lignin samples is lower by 6.4x and 16.3x compared to oxybenzone and octinoxate, respectively; however, it covers a wide absorption range in the UV spectrum. The lignin samples also showed good photostability and color stability, in contrast to the observed yellowing of octinoxate after 3 hours of exposure to sunlight. The UV spectra of some of the lignin samples indicate that their UV absorption capacity was enhanced by as much as 13.31% after exposure to sunlight.

Effects of Lipid Phase Content on the Technological and Sensory Properties of O/W Emulsions Containing Bemotrizinol-Loaded Nanostructured Lipid Carriers

Different lipid phase ratios (12, 14, and 16% w/w) were assessed for their ability to affect the technological and sensory properties of O/W emulsions in which bemotrizinol (BMTZ), a broad-spectrum sunscreen agent, was incorporated free or loaded into nanostructured lipid nanocarriers (NLC) to reduce its release from the vehicle and, hence, its skin permeation. The following technological properties were evaluated in vitro: spreadability, viscosity, pH, occlusion factor, BMTZ release, and sun protection factor (SPF). Sensory attributes were assessed by panelists in three different phases: before/during pick-up, rub-in, and after application. Raising the lipid phase ratio led to an increase in viscosity (from 8017 ± 143 cPs to 16,444 ± 770 cPs) and to a corresponding decrease in spreadability (from 9.35 ± 0.21 cm to 7.50 ± 0.10 cm), while the incorporation of BMTZ-loaded NLC determined a decrease in the occlusion factor (from 47.75 ± 1.16 to 25.91 ± 1.57) and an increase in SPF (from 6% for formulations containing 12% lipid phase to 15% for formulations containing 16% lipid phase). No BMTZ release was observed from all emulsions. Sensory attributes were mainly affected by the lipid phase ratio. These results suggest that the lipid phase ratio and BMTZ incorporation into NLC could contribute to determining the technological and sensory properties of O/W emulsions.

Know Your Sunscreen

Ultraviolet(UV) radiation from the sun has significant adverse effects on the skin, including sunburns, premature aging (photoaging), tanning, and many skin cancers. Sunscreens protect from harmful UV radiation. This article delves into the fundamentals of solar radiation, focusing on the UV spectrum, its effect on the skin, various types of sunscreens, and their mechanism of action to offer protection from harmful rays. UV exposure depends on factors like geographic location, altitude, time of day, season, and surface reflectivity. Sunscreen efficacy is measured by the Sun Protection Factor (SPF), which indicates how well a sunscreen can protect against UVB-induced sunburn. SPF ratings of 15, 30, and 50+ correspond to 93%, 96%, and 98% UVB blockage, respectively. In contrast, UVA protection lacks a standardized measure, with various in vitro and in vivo indices used globally. Sunscreens are categorized as organic (chemical) or inorganic (physical), each with distinct mechanisms and properties. Proper application of sunscreen, involving adequate coverage and reapplication, maximizes its protective benefits, significantly reducing the risk of UV-induced skin damage and cancers. Despite minor side effects like potential allergies, the advantages of sunscreen use, including prevention of sunburn, tanning, premature aging, and skin cancers, far outweigh the drawbacks. UV radiation from the sun poses significant risks to skin health. Understanding the nature and effects of UV radiation is crucial in appreciating the importance of protective measures such as sunscreen. The role of sunscreens in providing comprehensive protection cannot be overstated.

The Impact of Lignin Biopolymer Sources, Isolation, and Size Reduction from the Macro- to Nanoscale on the Performances of Next-Generation Sunscreen.

In recent years, concerns about the harmful effects of synthetic UV filters on the environment have highlighted the need for natural sun blockers. Lignin, the most abundant aromatic renewable biopolymer on Earth, is a promising candidate for next-generation sunscreen due to its inherent UV absorbance and its green, biodegradable, and biocompatible properties. Lignin's limitations, such as its dark color and poor dispersity, can be overcome by reducing particle size to the nanoscale, enhancing UV protection and formulation. In this study, 100-200 nm lignin nanoparticles (LNPs) were prepared from various biomass by-products (hardwood, softwood, and herbaceous material) using an eco-friendly anti-solvent precipitation method. Pure lignin macroparticles (LMPs) were extracted from beech, spruce, and wheat straw using an ethanol-organosolv treatment and compared with sulfur-rich kraft lignin (KL). Sunscreen lotions made from these LMPs and LNPs at various concentrations demonstrated novel UV-shielding properties based on biomass source and particle size. The results showed that transitioning from the macro- to nanoscale increased the sun protection factor (SPF) by at least 2.5 times, with the best results improving the SPF from 7.5 to 42 for wheat straw LMPs and LNPs at 5 wt%. This study underscores lignin's potential in developing high-quality green sunscreens, aligning with green chemistry principles.

Plectranthus scutellarioides (L.) R.Br. Leaf Extract as Sunscreen, Skin Lightening, and Antiaging

Plectranthus scutellaroides is a plant with attractive colored leaves. It contains secondary metabolite compounds such as flavonoids and phenolics, which provide skin protection against ultraviolet rays from the sun. The research aims to investigate the activity of P. scutellarioides leaf extract from various variants and different solvents on sunscreen, skin lightening, and anti aging activities. The best extract is formulated in gel dosage form. Each P. scutellaroides leaf was extracted using ethanol, ethyl acetate, and hexane as solvents. The obtained extract was assessed for Sun Protecting Factor (SPF), UVA Protection grade (PA), antioxidant activity, and inhibition of tyrosinase, collagenase, elastase, and hyaluronidase. Determination was conducted in vitro using spectrophotometric methods. The highest sunscreen activity was observed in the ethanol extract Va (Va-ET), which exhibited SPF and PA values of 25.618±0.265, and 0.681±0.007 (star 3), respectively at a concentration of 100 ug/mL. The most significant skin-lightening activity was observed in the ethanol extract Vc (Vc-ET), with an IC50 value inhibiting tyrosinase of 39.059 ug/mL. Regarding the anti-aging activity of the extracts, as determined by their antioxidant activity and inhibition of collagenase, elastase, and hyaluronidase, the most promising extracts were obtained from ethanol extract Va (Va-ET) and ethyl acetate extract Va (Va-EA), with IC50 values of 79.734, 76.838, 143.384, and 122.467 ug/ mL, respectively. The Va-ET was formulated into a gel dosage form, and there was a significant effect of the gelling agent on the SPF value of the extract after formulation (p < 0.05). All extracts exhibit activity as sunscreen, skin lightening, and anti-aging, with the Va-ET showing the highest efficacy. Gelling agents significantly influence the SPF value of extracts after formulation into the gel dosage form. Among them, F3, formulated from the Va-ET of P. scutellaroides using Carbopol-940 as a gelling agent, exhibits the highest efficacy.