A new lipophilic pro-vitamin C, tetra-isopalmitoyl ascorbic acid (VC-IP), prevents UV-induced skin pigmentation through its anti-oxidative properties

Topical retinoids: Novel derivatives, nano lipid-based carriers, and combinations to improve chemical instability and skin irritation

BACKGROUND

Retinoids, defined as synthetic or natural derivatives of vitamin A, have been extensively studied as anti-aging molecules that are widely applied in cosmetics. However, due to their physicochemical property, retinoids are highly unstable and extremely sensitive to light, oxygen, and temperature. Moreover, topical application of retinoids often leads to cutaneous irritation. These instabilities and irritant properties of retinoids limit their application in cosmetic and pharmaceutical products.

AIM

Our study aimed to provide a systematic review to summarize the mechanisms underlying the instability and irritant properties of retinoids, as well as recent developments in addressing these challenges.

METHODS

A comprehensive PubMed search was conducted using the following keywords: retinoids, chemical instability, skin irritation, retinoid derivatives, nano lipid-based carriers, liposomes, penetration-enhancer vesicles, ethosomes, niosomes, nanoemulsions, solid lipid nanoparticles, vitamins, soothing and hydrating agents, antioxidants and metal chelator and retinol combinations. Relevant researches published between 1968 and 2023 and studies related to these reports were reviewed.

RESULTS

The development of new retinoid derivatives, the utilization of new delivery systems like nano lipid-based carriers and the combination with other compounds like vitamins, soothing agents, antioxidants and metal chelator have been explored to improve the stability, bioavailability, and toxicity of the retinoid family.

CONCLUSIONS

Through advancements in formulation techniques, structure modification of retinoid derivatives and development of novel nano lipid-based carriers, the chemical instability and skin irritation of retinoids has been mitigated, ensuring their efficacy and potency over extended periods.

Cosmeceuticals for antiaging: a systematic review of safety and efficacy

Cosmeceuticals, the bridge between pharmaceuticals and cosmetics, contain biologically active ingredients that may improve the skin's overall appearance. As the market, accessibility, and popularity of cosmeceuticals increase, it is essential to understand the safety and efficacy of such products. This systematic review aims to examine published clinical studies involving the use of cosmeceuticals for antiaging to provide evidence-based recommendations based on available efficacy and safety data. PubMed, Embase, and Cochrane were systematically searched on January 1, 2023 using PRISMA guidelines. Strength of evidence was graded using the Oxford Centre for Evidence-Based Medicine guidelines. Clinical recommendations were made based on the quality of the existing literature. A total of 153 articles regarding the use of cosmeceuticals for treatment of antiaging were identified. After screening of titles, abstracts, and full text, 32 studies involving 1236 patients met inclusion criteria, including 20 randomized controlled trials (RCTs) and 12 non-randomized open-label clinical trials for Vitamin C, Retinol, Bakuchiol, Tetrahydrojasmonic acid, Growth Factors, Methyl Estradiolpropanoate, Timosaponin A-III (TA-III), Protocatechuic acid, Grammatophyllum speciosum, and Jasmine rice panicle extract. Retinol and vitamin C for antiaging received a Grade A for recommendation. Methyl estradiolpropanoate, bakuchiol, tetrahydrojasmonic acid, and growth factors received a recommendation grade of C. The remaining ingredients were assigned an inconclusive grade of recommendation due to lack of evidence. Cosmeceuticals included in the review had favorable safety profiles with few significant adverse events. The review analyzes numerous different ingredients to provide an evidence-based approach to decision-making for consumers and physicians on the use of cosmeceuticals for antiaging. Limitations to our review include a limited number of randomized controlled trials and a need for long-term data on each cosmeceutical's efficacy and safety. Future research is needed to establish the long-term effectiveness and safety of cosmeceuticals.

Effectiveness and tolerance of multicorrective topical treatment for infraorbital dark circles and puffiness

BACKGROUND

Treatment of infraorbital dark circles and under-eye puffiness is challenging due to its multifactorial nature and lack of broadly applicable, effective treatments. A daily skincare treatment option that is multimodal, effective, and tolerable across a broad patient population is an unmet need.

AIM

A multicorrective topical eye cream (MTEC) formulated with Tetrahexyldecyl (THD) ascorbate (vitamin C), prebiotic Inula Helenium, bioavailable peptides, botanical extracts, chrysin, and caffeine is hypothesized to improve the appearance of infraorbital dark circles and under-eye puffiness by targeting microvasculature congestion and permeability, melanin accumulation and hemoglobin degradation-related pigmentation, and skin health.

METHODS

An IRB approved, open-label, 12-week clinical study set out to evaluate the efficacy and tolerability of the MTEC across a broad patient population including varying ethnicities and Fitzpatrick Skin Types (FST). Female subjects (n = 40) ages 35-60 years old, with moderate-to-severe under-eye dark circles, moderate under-eye puffiness, and mild-to-moderate fine lines were enrolled into the study. Objective (Chromameter, VISIA® imaging, and Laser Doppler) and subjective assessments (clinical grading and self-assessment questionnaire) were conducted at baseline and post-baseline timepoints.

RESULTS

Thirty-seven subjects completed the study, and the MTEC efficaciously demonstrated short-term and long-term improvements in objective and subjective assessments across a broad patient population. Specifically, the MTEC demonstrated significant improvement of infraorbital dark circles, mainly by the reduction in microvasculature congestion and permeability, melanin, and hemoglobin degradation-related pigmentation.

CONCLUSION

Topical application of the MTEC may offer an effective and tolerable treatment option for infraorbital dark circles and puffiness.

Evidence-Based Utility of Adjunct Antioxidant Supplementation for the Prevention and Treatment of Dermatologic Diseases: A Comprehensive Systematic Review

Skin conditions are a significant cause of fatal and nonfatal disease burdens globally, ranging from mild irritations to debilitating diseases. Oxidative stress, which is an imbalance between reactive oxygen species and the cells' ability to repair damage, is implicated in various skin diseases. Antioxidants have been studied for their potential benefits in dermatologic health, but the evidence is limited and conflicting. Herein, we conducted a systematic review of controlled trials, meta-analyses, and Cochrane review articles to evaluate the current evidence on the utility of antioxidant supplementation for adjunct prevention and treatment of skin disease and to provide a comprehensive assessment of their role in promoting dermatologic health. The Cochrane Library, PubMed, EMBASE, and Epistemonikos databases were queried. Eligibility criteria included (1) primary focus on nanoparticle utility for skin cancer; (2) includes measurable outcomes data with robust comparators; (3) includes a number of human subjects or cell-line types, where applicable; (4) English language; and (5) archived as full-text journal articles. A total of 55 articles met the eligibility criteria for the present review. Qualitative analysis revealed that topical and oral antioxidant supplementation has demonstrated preliminary efficacy in reducing sunburns, depigmentation, and photoaging. Dietary exogenous antioxidants (namely vitamins A, C, and E) have shown chemopreventive effects against skin cancer. Antioxidant supplementation has also shown efficacy in treating non-cancer dermatoses, including rosacea, psoriasis, atopic dermatitis, and acne vulgaris. While further studies are needed to validate these findings on a larger scale, antioxidant supplementation holds promise for improving skin health and preventing skin diseases.

Acetyl Zingerone: A Photostable Multifunctional Skincare Ingredient That Combats Features of Intrinsic and Extrinsic Skin Aging

The cumulative damage skin sustains from exposure to environmental stressors throughout life exerts significant effects on skin aging and cancer development. One of the main ways by which environmental stressors mediate their effects within skin is through induction of reactive oxygen species (ROS). In this review, we chronicle the multiple properties by which acetyl zingerone (AZ) as a skincare ingredient can benefit skin (1) by helping manage overproduction of ROS through multiple routes as an antioxidant, physical quencher and selective chelator, (2) by fortifying protection after UV exposure ends to prevent the type of epidermal DNA damage that correlates with development of skin cancer, (3) by modulating matrisome activity and nurturing the integrity of the extracellular matrix (ECM) within the dermis and (4) through its proficient ability to neutralize singlet oxygen, by stabilizing the ascorbic acid precursor tetrahexyldecyl ascorbate (THDC) in the dermal microenvironment. This activity improves THDC bioavailability and may blunt pro-inflammatory effects of THDC, such as activation of type I interferon signaling. Moreover, AZ is photostable and can sustain its properties during UV exposure, in contrast to α-tocopherol. All these properties of AZ translate into measurable clinical benefits to improve the visual appearance of photoaged facial skin and to strengthen the skin's own defenses against sun damage.

Preparation and Spectroscopic Characterization of Ternary Inclusion Complexes of Ascorbyl Palmitate and Urea with γ-Cyclodextrin

A three-component inclusion complex of ascorbyl palmitate (ASCP), urea (UR), and γ-cyclodextrin (γCD) with a molar ratio of 1/12 has been prepared for the first time using the evaporation method (EVP method) and the grinding and mixing method (GM method). Also, we investigated changes in the physicochemical properties of the three-component complexes. The powder X-ray diffraction (PXRD) measurements showed ASCP, UR, and γCD characteristic peaks in the physical mixture (PM) (AU (ASCP/UR = 1/12)/γCD = 1/2). In GM (AU (ASCP/UR = 1/12)/γCD = 1/1), new diffraction peaks were observed around 2θ = 7.5° and 16.6°, while characteristic peaks derived from EVP (ASCP/UR = 1/12) were observed at 2θ = 23.4° and 24.9°. On the other hand, new diffraction peaks at 2θ = 7.4° and 16.6° were observed in GM (1/2). In the differential scanning calorimeter (DSC) measurement, an endothermic peak at around 83 °C was observed in the GM (1/1) sample, which is thought to originate from the phase transition of urea from the hexagonal to the tetragonal form. An endothermic peak around 113.9 °C was also observed for EVP (ASCP/UR = 1/12). However, no characteristic phase transition-derived peak or EVP (ASCP/UR = 1/12)-derived endothermic peak was observed in GM (1/2). Near infrared (NIR) spectroscopy of GM (1/2) showed no shift in the peak derived from the CH group of ASCP. The peaks derived from the NH group of UR shifted to the high and low wavenumber sides at 5032 cm−1 and 5108 cm−1 in EVP (ASCP/UR = 1/12). The peak derived from the OH group of γCD shifted, and the peak derived from the OH group of ASCP broadened at GM (1/2). These results suggest that AU (ASCP/UR = 1/12)/γCD prepared by the mixed grinding method formed inclusion complexes at the molar ratio (1/2).

Antioxidants in Sunscreens: Which and What For?

Ultraviolet (UV) radiation promotes the generation of reactive oxygen species (ROS) and nitrogen species (RNS), resulting in skin damage. Cosmetic industries have adopted a strategy to incorporate antioxidants in sunscreen formulations to prevent or minimize UV-induced oxidative damage, boost photoprotection effectiveness, and mitigate skin photoaging. Many antioxidants are naturally derived, mainly from terrestrial plants; however, marine organisms have been increasingly explored as a source of new potent antioxidant molecules. This work aims to characterize the frequency of the use of antioxidants in commercial sunscreens. Photoprotective formulations currently marketed in parapharmacies and pharmacies were analyzed with respect to the composition described on the label. As a result, pure compounds with antioxidant activity were found. The majority of sunscreen formulations contained antioxidants, with vitamin E and its derivatives the most frequent. A more thorough analysis of these antioxidants is also provided, unveiling the top antioxidant ingredients found in sunscreens. A critical appraisal of the scientific evidence regarding their effectiveness is also performed. In conclusion, this work provides an up-to-date overview of the use of antioxidants in commercial sunscreens for a better understanding of the advantages associated with their use in photoprotective formulations.

Safety Assessment of Ethers and Esters of Ascorbic Acid as Used in Cosmetics

The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the safety of 7 ethers and esters of ascorbic acid, which collectively function as antioxidants, skin-conditioning agents, skin protectants, fragrance ingredients, and skin bleaching agents in cosmetic products. The Panel reviewed relevant data relating to the safety of these ingredients, and concluded that the ethers and esters of ascorbic acid are safe in the present practices of use and concentration, as described in this safety assessment.

Evaluation of the anti-wrinkle effect of a lipophilic pro-vitamin C derivative, tetra-isopalmitoyl ascorbic acid

BACKGROUND

Tetra-isopalmitoyl ascorbic acid (VC-IP), an oil-soluble vitamin C derivative, is known to be effective for treating photoaging skin caused by oxidative stress. In addition, it is known that morphological changes of the skin occur on the face with aging, and the main cause has been reported to be photoaging.

AIMS

There have not been any published reports that examined the clinical effects of vitamin C derivatives on periorbital wrinkles. The purpose of this study was to characterize the potential anti-wrinkle effect of VC-IP.

METHODS

A double-blind, randomized, placebo-controlled, split face clinical trial was performed on 3 groups of 23 female subjects each who used 1%, 2%, or 3% VC-IP creams versus a placebo cream to treat their facial wrinkles. VC-IP cream was applied on the periorbital area on one side of the face of each subject twice a day for 8 weeks and a placebo cream was applied on the other side. Anti-wrinkle effects were evaluated by visual wrinkle grading and topographic assessments.

RESULTS

Periorbital wrinkles treated with VC-IP twice a day for 8 weeks showed marked or moderate improvements according to visual observations and grading of photographs. Moreover, topographic assessments confirmed the improving effects of VC-IP, and more interestingly, the appearance of those effects differed depending on the VC-IP concentration. In addition, sufficient improvement was observed in parameters reported to be associated with dermal structure at lower concentrations of VC-IP.

CONCLUSIONS

These results indicate that topical application of VC-IP cream reduces periorbital wrinkles caused by skin aging.

Preparation and Characterization of a Hybrid Complex of Cyclodextrin-Based Metal-Organic Frameworks-1 and Ascorbic Acid Derivatives

Cyclodextrin-based metal–organic frameworks-1 (CD-MOF-1) prepared using potassium hydroxide, ethanol, and γ-cyclodextrin (γ-CD) has been reported as a new type of MOF for the development of pharmaceutical formulations. The present study aimed to investigate the physicochemical properties of ascorbic acid derivatives (L-ascorbyl 6-palmitate (ASCP); L-ascorbyl 2,6-palmitate (ASCDP)) complexed with CD-MOF-1 by a solvent evaporation method. Powder X-ray diffraction revealed that the crystal diffraction pattern of CD-MOF-1 changed from α-type to β-type when prepared by a solvent evaporation method. For ASCP/CD-MOF-1 = 1/2 and ASCDP/CD-MOF-1 = 1/4 evaporated samples, the crystal diffraction peaks derived from ASCP and ASCDP disappeared, indicating a β-like behavior. Differential scanning calorimetry results revealed that the endothermic peaks of evaporated samples (ASCP/CD-MOF-1 = 1/2 and ASCDP/CD-MOF-1 = 1/4) were not detected due to melting. Furthermore, intermolecular interactions were observed in the hydrogen bonds between the CH groups of the side chains of ASCP and ASCDP and the OH group of CD-MOF-1 in (ASCP/CD-MOF-1 = 1/2) and EVP (ASCDP/CD-MOF-1 = 1/4), based on the near-infrared absorption spectroscopy analysis. CD-MOF-1 did not form inclusion complexes with the lactone rings of ASCP and ASCDP, but with the lipophilic side chains. These results suggested that CD-MOF-1 may be useful in preparing novel drug carriers for ASCP and ASCDP.

β-Nicotinamide Mononucleotide (NMN) Administrated by Intraperitoneal Injection Mediates Protection Against UVB-Induced Skin Damage in Mice

Objective

Ultraviolet light is an important environmental factor that induces skin oxidation, inflammation, and other diseases. Nicotinamide mononucleotide (NMN) has the effect of anti-oxidation and improving various physiological processes. This study explores the protective effect of NMN monomers given via intraperitoneal injection on UVB-induced photodamage.

Methods

We used a murine model of UVB-induced photodamage to evaluate the effect of an NMN monomer on photoaging skin by assessing skin and liver tissue sections, serum and skin oxidative stress levels, inflammatory markers, mRNA expression, and protein expression of skin- and liver-related genes.

Results

The results showed that NMN treatment blocked UVB-induced photodamage in mice, maintaining normal structure and amount of collagen fibers, normal thickness of epidermis and dermis, reducing the production of mast cells, and maintaining complete organized skin structure. NMN intraperitoneal injection also maintained the normal morphology of the mouse liver after UVB exposure. Meanwhile, NMN intraperitoneal injection was found to increase antioxidant ability and regulate the proinflammatory response of the skin and liver to UVB irradiation by enhancing the activity of antioxidant enzymes, release of anti-inflammatory cytokines, reduction of hydrogen peroxide production (H₂O₂), and decreased inflammatory cytokines. Furthermore, RT-qPCR results indicated that NMN reduced oxidative stress of skin and liver by promoting the activation of the AMP-activated protein kinase (AMPK) signaling pathway and further increasing the expression of downstream antioxidant genes of AMPK. RT-qPCR results also revealed that NMN treatment could downregulate the mRNA expression of interleukin (IL)-6, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α, and upregulate NF-kappa-B inhibitor-α (IκB-α) and interleukin (IL)-10 by inhibiting the activation of nuclear factor-κBp65 (NFκB-p65). Finally, NMN upregulated AMPK, IκB-α, SOD1, and CAT in the skin and downregulated NF-κBp65 protein expression, which is in line with the RT-qPCR results.

Conclusion

Based on the above results, NMN monomer treatment with intraperitoneal injection also block the photodamage caused by UVB irradiation in mice by regulating the oxidative stress response and inflammatory response.

A review of topical vitamin C derivatives and their efficacy

Vitamin C is a popular ingredient in over-the-counter cosmeceuticals due to its many biological functions in maintaining and improving skin health by treating UV damage, improving discoloration, and boosting collagen production. Several chemically modified derivatives of vitamin C have been developed in an attempt to increase the stability, percutaneous absorption, and overall activity of this ingredient in topical formulations. The goal of this review is to evaluate the differences between vitamin C derivatives that have been designed for cosmeceutical use and their efficacy.

Tetrahexyldecyl Ascorbate (THDC) Degrades Rapidly under Oxidative Stress but Can Be Stabilized by Acetyl Zingerone to Enhance Collagen Production and Antioxidant Effects

Tetrahexyldecyl Ascorbate (THDC) is an L-ascorbic acid precursor with improved stability and ability to penetrate the epidermis. The stability and transdermal penetration of THDC, however, may be compromised by the oxidant-rich environment of human skin. In this study, we show that THDC is a poor antioxidant that degrades rapidly when exposed to singlet oxygen. This degradation, however, was prevented by combination with acetyl zingerone (AZ) as a stabilizing antioxidant. As a standalone ingredient, THDC led to unexpected activation of type I interferon signaling, but this pro-inflammatory effect was blunted in the presence of AZ. Moreover, the combination of THDC and AZ increased expression of genes associated with phospholipid homeostasis and keratinocyte differentiation, along with repression of MMP1 and MMP7 expression, inhibition of MMP enzyme activity, and increased production of collagen proteins by dermal fibroblasts. Lastly, whereas THDC alone reduced viability of keratinocytes exposed to oxidative stress, this effect was completely abrogated by the addition of AZ to THDC. These results show that AZ is an effective antioxidant stabilizer of THDC and that combination of these products may improve ascorbic acid delivery. This provides a step towards reaching the full potential of ascorbate as an active ingredient in topical preparations.

Inhibition of persimmon tannin extract on guinea pig skin pigmentation

BACKGROUND

In daily life, excessive exposure to ultraviolet light can lead to pigmentation.

AIMS

This study is to determine the mechanism of persimmon tannin extract in inhibiting pigmentation, to investigate whether the effect of persimmon tannin extract is superior to that of arbutin, and to detect the optimal concentration.

METHODS

In this study, the guinea pig pigmentation model was established by ultraviolet B (UVB) irradiation. With arbutin as a positive control, Masson-Fontana silver staining was used to observe the effects of persimmon tannin extract on melanin distribution in guinea pigs' skin tissue. Then, the tyrosinase activity was measured, and an Enzyme-linked immunosorbent assay was used to investigate the contents of antioxidant enzymes, inflammatory factors, and signaling pathway inhibitors in guinea pigs' skin tissue.

RESULTS

The results showed that compared with the model group, superoxide dismutase, catalase, glutathione peroxidase, DKK1 content of Wnt/-catenin signaling pathway inhibitors levels, and inhibitory tyrosinase activity were increased by 24.3%, 33.3%, 59.3%, 36.81%, and 17.16%, respectively. Meanwhile, the interleukin-6 and interleukin-8 expression were reduced by approximately 22.2% and 54%. The results also showed that persimmon tannin extract could significantly reduce melanin density. The differences in experimental results were statistically significant (P < .01).

CONCLUSIONS

Compared with the arbutin group, the medium-dose group (persimmon tannin extract of 20%) had a more significant effect on inhibiting pigmentation. Persimmon tannin could serve as a promising agent for preventing skin pigmentation. It is expected to provide ideas for the development of deep-processed persimmon products related to functional foods and cosmetics.

Efficacy of topical antioxidants in the skin hyperpigmentation control: A clinical study by reflectance confocal microscopy

BACKGROUND

Some in vitro studies have reported the potential of antioxidants for the reduction of melanogenesis. However, it is important to assess the clinical efficacy of these substances in reducing skin hyperpigmentation. Thus, the aim of this study was to evaluate the clinical efficacy of dermocosmetic formulations based on antioxidants using Reflectance confocal microscopy (RCM).

METHODS

Thirty-two healthy females aged 39-55 years were enrolled and divided into four groups: Vehicle (V), V with ascorbyl tetraisopalmitate (ATIP), V with Spirulina sp., and V with hydroxytyrosol-titrated olive extract. Imaging analyses by high-resolution methods and RCM were performed in the malar region of the face before and after a 42-day period of application of the studied formulations.

RESULTS

Reflectance confocal microscopy imaging analyses showed a significant reduction of number of hyperreflective pixels and basal layer brightness after 42 days of application of formulations containing the antioxidants compared to vehicle and baseline values, suggesting an improvement of the skin pigmentation pattern.

CONCLUSION

Reflectance confocal microscopy permitted the identification of skin hyperpigmentation and the assessment of the clinical efficacy of dermocosmetic formulations based on antioxidants in a noninvasive way. All formulations containing antioxidants significantly reduced skin hyperpigmentation after the period of application.

Preparation and characterization of triamterene complex with ascorbic acid derivatives

The purpose of this study was to prepare solid dispersions of triamterene (TRT) with ascorbic acid (AA) or ascorbic acid 2 glucoside (AA2G) and to evaluate their physical properties. Solid dispersions were prepared by dissolving each sample in an organic solvent and evaporation (EVP). Powder X-ray diffraction (PXRD) revealed a halo pattern for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT = 1/1). In differential scanning calorimetry (DSC), endothermic peaks due to the melting of TRT and AA disappeared for EVP1 (AA/TRT = 1/1), and the melting peaks of TRT and AA2G disappeared for EVP2 (AA2G/TRT = 1/1). Fourier transform infrared (FT-IR) spectroscopy revealed broadened peaks for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT = 1/1) due to the hydroxyl groups (-OH) of AA and the amino groups (-NH2) of TRT and also revealed a peak shift due to the pteridine skeleton (C = N) of TRT. In near-infrared absorption (NIR) spectroscopy, peaks due to the hydroxyl groups (-OH) of AA and AA2G were found for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT = 1/1), respectively. A peak due to the amino groups (-NH2) was evident. This suggested the formation of an evaporation, in which TRT interacted with AA or AA2G. In the dissolution test, the dissolved fraction of TRT alone after 3 min was 30%, whereas the fractions were enhanced to approximately 90% for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT= 1/1). Results confirmed that dissolution properties were improved as a result of complex formation. The above findings indicated improvement the dissolution properties of TRT.

Effective lightening of facial melasma during the summer with a dual regimen: A prospective, open-label, evaluator-blinded study

BACKGROUND

Melasma is a chronic pigmentary condition that can have significant negative effects on quality of life. Vitamin C can be effective in the treatment melasma, but its delivery often proves to be challenging due to instability of the drug and subsequent cutaneous irritation at higher concentrations.

AIM

In this prospective, open-label, evaluator-blinded study, we aimed to assess the efficacy and tolerability of twice-daily application of a novel, highly potent, non-irritating 30% tetrahexyldecyl (THD) ascorbate serum in combination with 100% mineral-based sunscreen in the treatment of melasma during the summer months.

PATIENTS/METHODS

Ten female subjects of ages ranging from 18 to 60 years underwent twice-daily application of 30% THD ascorbate serum in combination with an anti-aging 100% mineral tinted broad-spectrum protection SPF 45 sunscreen moisturizer for 12 weeks during the summer months (July to September). Two blinded evaluators scored baseline and post-treatment photographs using the Griffiths' 10-point scale and global aesthetic improvement scale.

RESULTS

All subjects showed an improvement in hyperpigmentation with an average improvement of 33.7%. Seventy percent of subjects showed an improvement in skin tone evenness (redness), and among those subjects, the average improvement was 33.3%. The median global aesthetic improvement score was 2.0 (very much improved).

CONCLUSION

Our study demonstrated efficacy and safety in treating the pigmentary as well as vascular components of melasma with a novel 30% THD ascorbate serum and a purely mineral-based tinted moisturizing sunscreen.

Efficacy and safety of a 3-in-1 antiaging night facial serum containing melatonin, bakuchiol, and ascorbyl tetraisopalmitate through clinical and histological analysis

BACKGROUND

Changes induced by intrinsic and extrinsic photoaging result in signs of skin aging including altered pigmentation and wrinkles. A 3-in-1 night facial serum (NFS) was developed to treat skin aging by antioxidative and retinoid-like mechanisms.

OBJECTIVE

To determine the clinical and histological effects of the 3-in-1 NFS on signs of skin aging, clinically and histologically.

METHODS & MATERIALS

Twenty-four subjects applied serum nightly for 12 weeks, and 12 subjects continued an extension study to 24 weeks. Clinical assessment of skin quality was performed by dermatologists. Skin biopsy was performed at 12 weeks to assess histological changes.

RESULTS

There was a global aesthetic improvement over the duration of the study: +1.21 points at 12 weeks; +1.25 at 24 weeks. Skin texture, pigmentation, erythema, skin tone, complexion, lines, and wrinkles all significantly improved (P < .05). There was also a significant reduction in photodamage, hyperpigmentation, and wrinkle scores, most notably horizontal forehead expression lines, and marionette lines (P < .05 for all). Dermal and epidermal thickness increased without reaching statistical significance.

CONCLUSION

The 3-in-1 NFS had clinically and statistically significant effects on signs of skin aging after 12 weeks, which became more pronounced after 24 weeks.

Epidermal and Dermal Hallmarks of Photoaging are Prevented by Treatment with Night Serum Containing Melatonin, Bakuchiol, and Ascorbyl Tetraisopalmitate: In Vitro and Ex Vivo Studies

INTRODUCTION

Photoaging is a complex process that is chiefly the result of oxidative stress caused by ultraviolet (UV)-generated reactive oxygen species. To counter this process, we developed a 3-in-1 night facial serum (3-in-1 NFS) containing a combination of direct and indirect antioxidants and polyphenols that is designed to attenuate UV-generated free radicals and stimulate dermal protein synthesis. In clinical trials 3-in-1 NFS improved the appearance of photoaged skin. In this study we sought to identify some of the main histologic changes responsible for this.

METHODS

We performed an immunolabeling analysis of some of the salient epidermal and dermal proteins in 3-in-1 NFS-treated primary epidermal keratinocytes (HEKs) and dermal fibroblasts (HDFs) in vitro, and in UV-exposed skin explants ex vivo. Numbers of apoptotic sunburn cells following exposure of 3-in-1 NFS-treated skin explants to UV radiation were also determined.

RESULTS

We demonstrate that 3-in-1 NFS increases levels of filaggrin and aquaporin 3 in HEKs, and levels of collagen I and collagen III in HDFs in vitro. Levels of precursor procollagen type I and tropoelastin were increased in ex vivo skin explants. Numbers of apoptotic sunburn cells were significantly reduced in UV-exposed skin explants. These effects were only observed with the combination of ingredients in 3-in-1 NFS, suggesting that they have a synergistic effect on photoaged skin biology.

CONCLUSION

Our results show that some of the histological hallmarks of photoaging are improved with the use of 3-in-1 NFS.

Clinical evidence of the efficacy and safety of a new 3-in-1 anti-aging topical night serum-in-oil containing melatonin, bakuchiol, and ascorbyl tetraisopalmitate: 103 females treated from 28 to 84 days

BACKGROUND

Topical melatonin is a potent antioxidant, yet there have been few clinical studies on its anti-aging effects on the skin.

OBJECTIVES

To clinically assess the anti-aging efficacy and safety of a new 3-in-1 night facial serum (NFS) combining melatonin with bakuchiol, a novel retinol-like ingredient, and ascorbyl tetraisopalmitate, in all skin types.

METHODS

Five clinical studies were performed, with a total of 103 subjects treated from 28 to 84 days. Under dermatologist supervision, a 3-month efficacy and safety study evaluated anti-aging properties by clinical scoring and instrumental evaluations. Two studies evaluated skin hydration properties for 12 hours after a single application of NFS. Two studies were performed in oily skin: a 1-month efficacy and safety study and a 1-month comedogenesis study.

RESULTS

After 12 weeks, clinical evaluation showed a statistically significant decrease in wrinkles (11%), an increase in skin firmness (8%), a reduction in redness (70%; P < 0.01 for all), and an overall improvement in skin quality and complexion. The reduction in wrinkles and the increase in skin firmness were also supported by instrumental evaluations (Dermatop and Dynaskin). Hydration levels increased significantly from 30 minutes until 12 hours and transepidermal water loss significantly decreased after 4H and 6H. Subjects favorably evaluated the efficacy and cosmetic properties of the serum, and it was well tolerated in all skin types including oily skin.

CONCLUSIONS

This 3-in-1 NFS showed significant clinical anti-aging effects when applied once daily and was well tolerated.

Ascorbic Acid Mitigates D-galactose-Induced Brain Aging by Increasing Hippocampal Neurogenesis and Improving Memory Function

Ascorbic acid is essential for normal brain development and homeostasis. However, the effect of ascorbic acid on adult brain aging has not been determined. Long-term treatment with high levels of D-galactose (D-gal) induces brain aging by accumulated oxidative stress. In the present study, mice were subcutaneously administered with D-gal (150 mg/kg/day) for 10 weeks; from the seventh week, ascorbic acid (150 mg/kg/day) was orally co-administered for four weeks. Although D-gal administration alone reduced hippocampal neurogenesis and cognitive functions, co-treatment of ascorbic acid with D-gal effectively prevented D-gal-induced reduced hippocampal neurogenesis through improved cellular proliferation, neuronal differentiation, and neuronal maturation. Long-term D-gal treatment also reduced expression levels of synaptic plasticity-related markers, i.e., synaptophysin and phosphorylated Ca²⁺/calmodulin-dependent protein kinase II, while ascorbic acid prevented the reduction in the hippocampus. Furthermore, ascorbic acid ameliorated D-gal-induced downregulation of superoxide dismutase 1 and 2, sirtuin1, caveolin-1, and brain-derived neurotrophic factor and upregulation of interleukin 1 beta and tumor necrosis factor alpha in the hippocampus. Ascorbic acid-mediated hippocampal restoration from D-gal-induced impairment was associated with an enhanced hippocampus-dependent memory function. Therefore, ascorbic acid ameliorates D-gal-induced impairments through anti-oxidative and anti-inflammatory effects, and it could be an effective dietary supplement against adult brain aging.

An open-label, single-site study to evaluate the tolerability, safety, and efficacy of using a novel facial moisturizer for preparation and accelerated healing pre and post a single full-face radiofrequency microneedling treatment

BACKGROUND

Skincare cosmeceutical products have been shown to address intrinsic and extrinsic skin aging. Radiofrequency (RF) with microneedling is effective and safe in improving skin laxity and texture. Pairing skincare cosmeceutical products pre- and post-procedure is beneficial as it enhances patient results, patient results, patient experience, and reduces patient downtime.

OBJECTIVE

To evaluate the tolerability, safety, and efficacy of a multi-ingredient anti-aging facial moisturizer when applied pre- and post-procedure consisting of a single RF microneedling treatment.

METHOD

Fifteen female patients, aged 37-60, Fitzpatrick skin types I-IV, with mild-to-moderate wrinkles were included in the study. Patients applied a multi-ingredient anti-aging facial moisturizer twice a day (morning and night) two weeks prior to RF microneedling and four weeks post-RF microneedling (twice a day). At each time point, investigator objective assessment, self-assessments, and clinical photography were taken.

RESULT

There were no adverse events as evaluated by the investigator. For this combined treatment and procedure patient scored comfort as the highest for satisfaction. Tolerability parameters erythema and edema were reported after RF microneedling treatment and were significant compared to the pre-procedure timepoint. Eighty percent of patients showed an improvement in Glogau Wrinkle Scale, but improvement was not statistically significant between baseline and end of study. Improvements in all skin attributes (radiance, tone, smoothness, texture, redness, dryness, and overall appearance) were statistically significant at the end of the study. Self-perceived skin attribute improvements included overall improvement, brightness, texture, pigmentation, redness, and tightness. The combination of the anti-aging facial moisturizer and RF microneedling was recommended by the patients in this study.

CONCLUSION

This clinical study positively supports the hypothesis that combining the multi-ingredient anti-aging facial moisturizer pre- and post-RF microneedling was safe and tolerable for the patients.

Usefulness of Urea as a Means of Improving the Solubility of Poorly Water-Soluble Ascorbyl Palmitate

The aim of this study was to evaluate complexes of L-ascorbyl palmitate (ASCP) and urea (UR). This evaluation involved differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), near-infrared spectroscopy (NIR), a solubility test, a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test, and a mushroom tyrosinase inhibition assay. Physicochemical evaluation revealed that ASCP/UR complexes form at a molar ratio of 1/12. The solubility test revealed that ASCP/UR complexes had increased solubility compared to ASCP. The DPPH radical scavenging test and mushroom tyrosinase inhibition assay revealed that the activity of ASCP/UR complexes was not impaired by complex formation. These results are probably due to the tetragonal crystal system of UR changing to a hexagonal crystal system and interaction with the alkyl group of ASCP.

Ascorbyl Tetraisopalmitate Inclusion into Υ-Cyclodextrin and Mesoporous SBA-15: Preparation, Characterization and In Vitro Release Study

Ascorbic acid or vitamin C is a strong antioxidant widely used in cosmetic and food fields. This vitamin is very unstable and rapidly undergoes degradation. In order to solve this problem and to obtain a stable ascorbic acid, Nikkol Group has developed ascorbyltetraisopalmitate (VC-IP). This raw material is an oil phase, already well-known and employed in the cosmetic market. The objective of this study is to obtain VC-IP in micro-powder form, in order to produce a new raw material that is easily dispersible in oil and water phases and useful for make-up and color cosmetic applications. Various types of drug carriers were studied and considered in order to support VC-IP and obtain the conversion in powder. Υ-cyclodextrin and mesoporous silica SBA-15 were chosen as the best candidates. A white powder of supported VC-IP was obtained with each carrier (VC-IP@cyclodextrin, VC-IP@SBA-15). The systems underwent physicochemical characterization and in vitro release tests were carried out. Based on the conducted study, it can be concluded that by supporting VC-IP on Υ-cyclodextrin and SBA-15, it is feasible to obtain a new raw material in powder form. The two carriers possess different release profiles, adding the possibility to finely tune the release of the active component in smart formulations.

Bio-inspired strategy for controlled dopamine polymerization in basic solutions

Here we describe a facile and convenient method to achieve both spatial and temporal control of dopamine polymerization under basic conditions by the cooperative action of sodium ascorbate and UV irradiation.

Effects of Microbubble Size on Ultrasound-Induced Transdermal Delivery of High-Molecular-Weight Drugs

The transdermal delivery of a wide range of high-molecular-weight drugs is limited by the stratum corneum layer of the epidermis representing a significant barrier to penetration across the skin. This study first determined the different effects of different-size ultrasound (US) contrast agents and microbubbles (MBs) for enhancing the transdermal delivery of high-molecular-weight drugs. The effects of US-mediated different-size (1.4, 2.1, and 3.5 μm) MBs (as a contrast agent) and ascorbyl tetraisopalmitate (VC-IP) on enhancing skin transdermal delivery were demonstrated both in vitro and in vivo. The results indicated that at a power density of 3 W/cm² the penetration depth in group US combined with 3.5-μm MBs and penetrating VC-IP (U+3.5) was 34% and 14% higher than those in groups US combined with 1.4-μm MBs and penetrating VC-IP (U+1.4) and US combined with 2.1-μm MBs and penetrating VC-IP (U+2.1), respectively, for the agarose phantoms, while the corresponding increases for pigskin were 37% and 19%.In terms of the skin permeation of VC-IP, the VC-IP concentration in group U+3.5 was 23% and 10% higher in than those in groups U+1.4 and U+2.1, respectively. The whitening effect (luminosity index) of mice skin in group U+3.5 had increased (significantly) by 28% after 1 week, by 34% after 2 weeks, and tended to stabilize after 3 weeks (45%) in C57BL/6J mice over a 4-week experimental period. The results obtained in this study indicate that combining US with MBs of different sizes can produce different degrees of skin permeability so as to enhance the delivery of VC-IP to inhibit melanogenesis, without damaging the skin in mice.

Orange peel extract, containing high levels of polymethoxyflavonoid, suppressed UVB-induced COX-2 expression and PGE2 production in HaCaT cells through PPAR-γ activation

Ultraviolet light (UV) induces an inflammatory response in the skin by cyclooxygenase (COX)-2 expression and prostaglandin (PG) E2 production. Citrus peel has been used as a natural medicine. It contains polymethoxyflavonoids (PMFs) as a major ingredient, which have anti-inflammatory activity. We obtained orange peel extract containing high levels of PMFs. The extract suppressed UVB-induced COX-2 expression and PGE2 production in HaCaT cells. Furthermore, it was found that this extract acted as a peroxisome proliferator-activated receptor (PPAR)-γ agonist. The suppression of UVB-induced COX-2 expression by this extract was inhibited by GW 9662 and T0070907, which are both PPAR-γ antagonists. It is therefore suggested that orange peel extract, containing high levels of PMFs, suppresses UVB-induced COX-2 expression and PGE2 production through PPAR-γ. Hence, these extracts could provide useful protection against or alleviation of UV damage.

Modified cellulose nanocrystal for vitamin C delivery

Cellulose nanocrystal grafted with chitosan oligosaccharide (CNC-CSOS) was used to encapsulate vitamin C and prepare CNCS/VC complexes using tripolyphosphte via ionic complexation. The stability of vitamin C and the antioxidant activity of the CNCS/VC complexes were elucidated. The formation of the complex was confirmed using DSC and UV-vis spectrophotometry, and TEM was used to study the morphology of the complexes. The encapsulation efficiency of vitamin C at pH 3 and 5 was 71.6% ± 6.8 and 91.0 ± 1.0, respectively. Strong exothermic peaks observed in isothermal titration calorimetric (ITC) studies at pH 5 could be attributed to additional electrostatic interactions between CNC-CSOS and vitamin C at pH 5. The in vitro release of vitamin C from CNCS/VC complexes showed a sustained release of up to 20 days. The vitamin C released from CNCS/VC complex displayed higher stability compared with the control vitamin C solution, and this was also confirmed from the ITC thermograms. CNC-CSOS possessed a higher scavenging activity and faster antioxidant activity compared with its precursors, i.e., oxidized CNC and CSOS and their physical mixtures. Complexing vitamin C into CNC-CSOS particles yielded a dynamic antioxidant agent, where the vitamin C is released over time and displayed sustained antioxidant properties. Therefore, CNCS/VC can potentially be used in cosmeceutical applications as topical formulations.

CAM use in dermatology. Is there a potential role for honey, green tea, and vitamin C?

Complementary and alternative medicine (CAM) is a group of non-traditional medical practices that includes natural products, manipulations, and mind and body medicine. CAM use has grown and become popular among patients. In dermatology, honey, green tea, and vitamin C have been used as topical treatments for a variety of diseases. We performed a systematic review to explore the cutaneous effects of each of these three products. Honey's unique antibacterial, anti-inflammatory, and antioxidant properties were shown to contribute to wound healing, especially in ulcers and burns. Green tea, among many health benefits, demonstrated protection from ultraviolet-induced events, such as photoimmunosuppression and skin cancer growth. Vitamin C, known for its antioxidant properties and key role in collagen production, has been shown to produce positive effects on skin hyperpigmentation and aging. Future large well-designed clinical trials are needed in order to further investigate the potential of these agents as dermatological therapies.

Stability, transdermal penetration, and cutaneous effects of ascorbic acid and its derivatives

Topically applied antioxidants exert their benefits by offering protection from damaging free radicals and over-the-counter cosmeceuticals incorporating antioxidants are among the most popular anti-aging products available. One potent antioxidant of particular note, vitamin C, has been extensively utilized because it possesses a variety of other cutaneous benefits including photoprotection from UV A & B, neocollagenesis, inhibition of melanogenesis and improvement of a variety of inflammatory skin disorders. However, the instability of this water-soluble vitamin, together with difficulties associated with its topical delivery, has presented issues for the formulation chemist. This article reviews the scientific data and clinical studies that underpin the stability, percutaneous absorption, and cutaneous effects of vitamin C together with its commonly utilized, commercially available derivatives.

Benefits of combinations of vitamin A, C and E derivatives in the stability of cosmetic formulations

Chemically stable ester derivatives of vitamins A, C and E have become a focus of interest for their role in the satisfactory results in skin aging treatments. Accordingly, the aim of this study was to evaluate the physical and chemical stability of a cosmetic formulation containing 1% retinyl palmitate, ascorbyl tetraisopalmitate and tocopheryl acetate, alone or in combination. In the studies of physical stability, a Brookfield rheometer was used to determine rheological behavior of formulations containing the vitamins. Chemical stability was determined by HPLC on a Shimadzu system with UV detection. Results showed that formulations had pseudoplastic behavior and that vitamins did not alter their apparent viscosity and thixotropy. In the chemical stability studies, first-order reaction equations were used for determinations of the shelf-life of vitamins derivatives considering a remaining concentration of 85%. Combined vitamins in a single formulation had a slightly lower degradation rate as compared to different preparations containing only one of the vitamins. Considering that many cosmetic formulations contain vitamin combinations it is suggested that the present study may contribute to the development of more stable formulations containing liposoluble vitamins.

Permeation enhancement of ascorbic acid by self-dissolving micropile array tip through rat skin

Ascorbic acid (AA) loaded self-dissolving micropiles (SDMP) were prepared using chondroitin sulfate as the base for the percutaneous administration of AA. AA solution was added to dense solution of chondroitin solution, glue, and array tip, 1.0 cm(2), containing 100 SDMPs of which length was 500 microm and basal diameter was 300 microm, were prepared. Two kinds of AA array tips containing 1344.2+/-1.7 microg (high content ones) and 638.7+/-4.3 microg (low content ones) were used. In vitro dissolution study showed that more than 90% of AA were released from both SDMP array tips within 5 min. Stability experiment showed that 99.2-99.4% of AA was detected in SDMP array tips when stored at 23 degrees C for 1 week. When in vitro permeation experiments were performed after AA SDMP array was inserted to the isolated rat abdominal skin, extremely high amounts of AA, 1285.3+/-369.0 microg (95.3%) for high content SDMP tip and 405.6+/-84.3 microg (65.8%) for low content SDMP tip, were permeated for 6 h into the receptor compartment due to the break down of the skin barrier function. When AA SDMP array tip was administered to the rat skin under anesthetized condition with the different contact times, 10, 20 and 30 min, the permeated amount of AA was dependent on both the AA content in SDMP array tips and the contact time. When AA SDMP was contact to the skin for 30 min, permeated amounts of AA were 146.8+/-22.9 microg (10.9%) for high content-SDMP tip and 61.2+/-18.2 microg (9.6%) for low content SDMP tip. These results suggest the usefulness of SDMP array tip for the percutaneous absorption of AA.

Role of antioxidants in the skin: anti-aging effects

Intracellular and extracellular oxidative stress initiated by reactive oxygen species (ROS) advance skin aging, which is characterized by wrinkles and atypical pigmentation. Because UV enhances ROS generation in cells, skin aging is usually discussed in relation to UV exposure. The use of antioxidants is an effective approach to prevent symptoms related to photo-induced aging of the skin. In this review, the mechanisms of ROS generation and ROS elimination in the body are summarized. The effects of ROS generated in the skin and the roles of ROS in altering the skin are also discussed. In addition, the effects of representative antioxidants on the skin are summarized with a focus on skin aging.

Cytoprotective effects of the lipoidic-liquiform pro-vitamin C tetra-isopalmitoyl-ascorbate (VC-IP) against ultraviolet-A ray-induced injuries in human skin cells together with collagen retention, MMP inhibition and p53 gene repression

Irradiation with ultraviolet-A (UVA) ray at doses of 20-100 J/cm(2) diminished the cell viability of human keratinocytes HaCaT and human melanoma cells HMV-II, both of which were protected by pre-irradiational administration with the ascorbic acid (Asc) derivative, VC-IP (2,3,5,6-O-tetra-2'-hexyldecanoyl-L-ascorbic acid; vitamin C-isopalmityl tetraester), which is the first lipoidic-liquiform pro-vitamin C by itself that is materialized by esterization of all four intramolecular hydroxyl groups of an Asc molecule with branched chain fatty groups, resulting in molecular fluidity higher than that of the corresponding straight chains. Irradiation with UVA to HaCaT keratinocytes was shown to cause the formation of 8-hydroxydeoxyguanosine (8-OHdG), translocation of phosphatidylserine in the inner layer into the outer layer of cell membrane, and lowering of a mitochondrial membrane potential, all of which were repressed by pre-irradiational administration with VC-IP. Expression of p53 gene, another hallmark of UV-induced DNA damages, was promoted by UVA irradiation to the keratinocytes but also repressed by VC-IP. Administration with VC-IP of 10-50 microM to human fibroblasts NHDF achieved the enhancement of collagen synthesis, repression of matrix metalloprotease-2/9 activity, and increasing of intracellular Asc contents more markedly than that with Asc itself of the same concentrations. Thus UVA-induced diverse harmful effects could be prevented by VC-IP, which was suggested to ensue intrinsically from the persistent enrichment of intracellular Asc, through esterolytic conversion of VC-IP to a free-form Asc molecule, resulting in relief to UVA-caused oxidative stress.

Co-localization of inducible nitric oxide synthase and phosphorylated Akt in the lesional skins of patients with melasma

Activation of the inducible nitric oxide synthase (iNOS)/nitric oxide (NO) pathway in keratinocytes has been reported to be associated with the pathogenesis of melanogenesis. Akt activation plays an important role in the activation of the transcription factor nuclear factor (NF)-kappaB and subsequent elevation of iNOS expression. In the present study, we highly detected both iNOS protein and Akt phosphorylation in keratinocytes of the basal layer of the epidermis at the junction with the dermis of melasma skin biopsy specimens, but not in normal skin tissues, from nine patients using immunohistological analysis. iNOS protein and phosphorylated Akt were co-localized in the lesional skins, and their levels were highly correlated R2= 0.69). Furthermore, iNOS mRNA was also detected in an additional three skin biopsy specimens, but not in normal skin, by reverse transcription polymerase chain reaction. Our results describe that iNOS expression is elevated in human melasma lesions, probably via activation of the Akt/NF-kappaB pathway, indicating that NO production plays an important role in the mechanism of hyperpigmentation in human facial melasma.

Intravenous vitamin C in the treatment of post-laser hyperpigmentation for melasma: a short report

Melasma is difficult to treat. Vitamin C, topical and by iontophoresis, has been shown to be useful. When lasers are used, there is a significant incidence of post-laser hyperpigmentation. There is no single established treatment for the latter. The case history of a 51-year-old Chinese woman is presented. Intravenous vitamin C appears to be useful in treating this complication.

Evaluation of erythemal UV effective irradiance from UV lamp exposure and the application in shield metal arc welding processing

Ultraviolet radiation (UVR) exposure is known to cause potential effects such as erythema in skin. For UV-induced erythema (sunburn), the action spectrum from the Commission Internationale de l'Eclairage, International Commission on Illumination (CIE) was adopted. Erythemal UV effects from UVR lamp exposure were investigated with commercial spectroradiometry devices in this research. Three kinds of portable UV germicidal lamps with broadband UVA (BB UVA, 350-400 nm), broadband UVB (BB UVB, 280-350 nm), and narrowband UVC (NB UVC, 254 nm) wavelengths served as the UVR emission sources. An action spectrum expresses the effectiveness of radiation for assessing the hazard of UVR in the erythemal action spectrum from 250-400 nm. The UV Index (UVI) is an irradiance scale computed by multiplying the CIE erythemal irradiance integral in milliwatts per square meter by 0.04 m mW. A comprehensive approach to detecting erythemal UVR magnitude was developed to monitor the effective exposure from UV lamps. The erythemal UVR measurement was established and the exposure assessment was applied to monitor erythemal UVR magnitude from shield metal arc welding (SMAW) processing. From this study, the erythemal UVR exposures were assessed and evaluated with environmental solar simulation of the UVI exposure.

Role of novel delivery systems in developing topical antioxidants as therapeutics to combat photoageing

Ageing proceeds by highly complicated biochemical processes, in which the involvement of the reactive oxygen species (ROS) and free radicals has been implicated. Reactive oxygen species are dramatically enhanced by exposure to the ultraviolet radiation. Free radical scavengers and antioxidants can thus provide a long-term protection against these changes. Currently, dermaceutical and cosmetic industry is growing immensely with its main focus on packaging the active into a suitable/novel delivery system. This not only enhances the customer acceptance but offers better targeting to the upper skin layer, with faster onset, at a lower concentration of the active. Later also counter toxic or adverse effects observed with large doses especially when administered orally. Several of the antioxidant molecules are labile to degradation in the presence of oxygen, water and light, hence it becomes all the more appropriate to use a delivery system which will augment their stability and hence enhance the performance. In the present review, we focus on the pioneering research on novel delivery systems which can promote the therapeutic value of antioxidants for combating UV-induced photoageing.