Encapsulation of ethylhexyl methoxycinnamate, a light-sensitive UV filter, in lipid nanoparticles

Photochemical and Oxidative Degradation of Chamazulene Contained in Artemisia, Matricaria and Achillea Essential Oils and Setup of Protection Strategies

Chamazulene (CA) is an intensely blue molecule with a wealth of biological properties. In cosmetics, chamazulene is exploited as a natural coloring and soothing agent. CA is unstable and tends to spontaneously degrade, accelerated by light. We studied the photodegradation of CA upon controlled exposure to UVB-UVA irradiation by multiple techniques, including GC-MS, UHPLC-PDA-ESI-MS/MS and by direct infusion in ESI-MSn, which were matched to in silico mass spectral simulations to identify degradation products. Seven byproducts formed upon UVA exposure for 3 h at 70 mW/cm2 (blue-to-green color change) were identified, including CA dimers and CA benzenoid, which were not found on extended 6 h irradiation (green-to-yellow fading). Photostability tests with reduced irradiance conducted in various solvents in the presence/absence of air indicated highest degradation in acetonitrile in the presence of oxygen, suggesting a photo-oxidative mechanism. Testing in the presence of antioxidants (tocopherol, ascorbyl palmitate, hydroxytyrosol, bakuchiol, γ-terpinene, TEMPO and their combinations) indicated the highest protection by tocopherol and TEMPO. Sunscreens ethylhexyl methoxycinnamate and particularly Tinosorb® S (but not octocrylene) showed good CA photoprotection. Thermal stability tests indicated no degradation of CA in acetonitrile at 50 °C in the dark for 50 days; however, accelerated degradation occurred in the presence of ascorbyl palmitate.

Nanoparticles as a Therapeutic Delivery System for Skin Cancer Prevention and Treatment

The use of nanoparticles (NPs) as a therapeutic delivery system has expanded markedly over the past decade, particularly regarding applications targeting the skin. The delivery of NP-based therapeutics to the skin requires special consideration owing to its role as both a physical and immunologic barrier, and specific technologies must not only take into consideration the target but also the pathway of delivery. The unique challenge this poses has been met with the development of a wide panel of NP-based technologies meant to precisely address these considerations. In this review article, we describe the application of NP-based technologies for drug delivery targeting the skin, summarize the types of NPs, and discuss the current landscape of NPs for skin cancer prevention and skin cancer treatment as well as future directions within these applications.

Salicin and Hederacoside C-Based Extracts and UV-Absorbers Co-Loaded into Bioactive Lipid Nanocarriers with Promoted Skin Antiaging and Hydrating Efficacy

Conventional and herbal active principles can be combined in a beneficial harmony using their best features and compensating for the certain weaknesses of each. The study will answer the question, “how can willow bark extract (Wbe) or ivy leaf extract (Ile) influence the photoprotective, skin permeation and hydration properties of Bioactive Lipid Nanocarriers (BLN) loaded with UV-filters and selected herbals?”. BLN-Wbe/Ile-UV-filters were characterized for particle size, zeta potential, thermal behavior, entrapment efficiency and drug loading. The formulated BLN-hydrogels (HG) were subjected to in vitro release and permeation experiments. The in vitro determination of sun protection factors, as well as comparative in vitro photostability tests, rheology behavior and in vivo hydration status have been also considered for hydrogels containing BLN-Ile/Wbe-UV-filters. Photoprotection of BLN-HG against UVA rays was more pronounced as compared with the UVB (UVA-PF reached values of 30, while the maximum SPF value was 13). The in vitro irradiation study demonstrated the photostability of BLN-HG under UV exposure. A noteworthy cosmetic efficacy was detected by in vivo skin test (hydration effect reached 97% for the BLN-Wbe-UV-filters prepared with pomegranate oil). The research novelty, represented by the first-time co-optation of the active herbal extracts (Wbe and Ile) together with two synthetic filters in the same nanostructured delivery system, will provide appropriate scientific support for the cosmetic industry to design novel marketed formulations with improved quality and health benefices.

Shared Makeup Cosmetics as a Route of Demodex folliculorum Infections

Purpose

The aim of the study was to examine Demodex survival in makeup cosmetics, i.e., powder cream, mascara, and lipstick, and to determine whether cosmetics shared with others can be a source of D. folliculorum infection.

Methods

Live D. folliculorum adults were placed in cosmetic samples and their motility was observed under a microscope. The mites were fully or partially immersed in the powder cream and lipstick, and only partially immersed in the mascara. Partial immersion means that only the opisthosoma was covered by the cosmetic, whereas the gnathosoma and podosoma had no contact with the cosmetic. Cessation of motility was regarded as a sign of death.

Results

In the control (mites placed on a microscope slide with no cosmetics), the survival time was 41.2 h. D. folliculorum that were immersed fully or partially in the lipstick substrate were viable for 38.5 h and 148 h, respectively. The survival time of the mites at full and partial immersion in the powder cream was 0.78 h and 2.16 h, respectively. The average survival time in the mascara was 21 h.

Conclusions

Makeup cosmetics used by different individuals at short intervals (from several hours to several days) can be a source of transmission of Demodex sp. mites.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11686-020-00332-w.

Nanocarriers and Microcarriers for Enhancing the UV Protection of Sunscreens: An Overview

This review addresses a major question of importance to pharmaceutical scientists: how can novel drug delivery systems play a role in maximizing the UV protection of sunscreens? Because more and more people are being diagnosed with skin cancer each year than all other cancers combined, adequate sun protective measures are pivotal. In this context, the present review is to give an up-to-date overview on the different nanocarrier systems that have been explored so far for encapsulating different types of UV filters present on the market. The aim of these carrier systems is to prevent skin penetration and to enhance the photoprotective potential of sunscreen actives. For each supramolecular system, a brief description along with the studies, achievements, and pitfalls, on the type of UV actives inside them, ranging from classical UV filters to new generation of UV actives is given. A brief overview of UV filters encapsulated in microcarriers is also discussed.

Using ordered mesoporous silica SBA-15 to limit cutaneous penetration and transdermal permeation of organic UV filters

Avobenzone (AVO), oxybenzone (OXY), and octyl methoxycinnamate (OMC), are widely used UV filters. The aim of this study was to investigate the effect of incorporation in mesoporous silica (SBA-15) on their cutaneous deposition and permeation. Stick formulations containing "free" and "incorporated" UV filters (SF1 and SF2, respectively) were prepared and characterized with respect to their physicochemical, thermal, and functional properties. Cutaneous delivery experiments using porcine skin with quantification by UHPLC-MS/MS, demonstrated that skin deposition of AVO and OXY after application of SF2 for 6 and 12 h was significantly lower than that from SF1 at each time-point (Student t-test, p < 0.05): e.g. OXY permeation across the skin was 30-, 12- and 1.5-fold lower after 6, 12 and 24 h, respectively, following application of SF2. Cutaneous biodistribution profiles of AVO and OXY to 800 µm evidenced a significant decrease in the amounts in the viable epidermis and dermis. In contrast, deposition of the more lipophilic OMC was not significantly different (p ˃ 0.05). In vitro photoprotective efficacy results demonstrated that adsorption/entrapment of UV filters enhanced the sun protection factor by 94%. In conclusion, SBA-15, an innovative mesoporous material, increased photoprotection by UV filters while reducing their cutaneous penetration and transdermal permeation.

Dual-Prevention for UV-Induced Skin Damage: Incorporation of Melatonin-Loaded Elastic Niosomes into Octyl Methoxycinnamate Pickering Emulsions

Incorporation of antioxidants into sunscreens is a logical approach, yet co-delivery of them with UV filters is a challenge. Here, we purposed a combination therapy, in which the chemical UV filter, octyl methoxycinnamate, was accumulated on upper skin while the antioxidant, melatonin, can penetrate deeper layers to show its effects. Melatonin-loaded elastic niosomes and octyl methoxycinnamate Pickering emulsion were prepared separately. Lyophilized elastic niosomes were dispersed into the Pickering emulsion to prepare the proposed combination formulation. The characterization studies of the formulations revealed that elastic niosomes can be prepared with tunable nanometer sizes, whereas Pickering emulsions can encapsulate the UV filter in micrometer-sized droplets. Melatonin-loaded elastic niosomes prepared with Tween80/Span80 mixture were 146 nm with a PI of 0.438, and 58.42% entrapment efficiency was achieved. The mean diameter size of the combination formulation was 27.8 μm. Ex vivo permeation studies revealed that 7.40% of octyl methoxycinnamate and 58% of melatonin were permeated through the rat skin while 27.6% octyl methoxycinnamate and 37% of melatonin accumulated in the skin after 24 h. Cell culture studies with real-time cell analyzer showed that the proposed formulation consist of melatonin-loaded elastic niosomes and octyl methoxycinnamate Pickering emulsion had no negative effect on the cell proliferation and viability. According to α,α-diphenyl-β-picrylhydrazyl free radical scavenging method, the proposed formulation showed as high antioxidant activity as melatonin itself. It is concluded that the proposed formulation would be a promising dual therapy for UV-induced skin damage with co-delivery strategy.

Different DNA damage response of cis and trans isomers of commonly used UV filter after the exposure on adult human liver stem cells and human lymphoblastoid cells

2-ethylhexyl 4-methoxycinnamate (EHMC), used in many categories of personal care products (PCPs), is one of the most discussed ultraviolet filters because of its endocrine-disrupting effects. EHMC is unstable in sunlight and can be transformed from trans-EHMC to emergent cis-EHMC. Toxicological studies are focusing only on trans-EHMC; thus the toxicological data for cis-EHMC are missing. In this study, the in vitro genotoxic effects of trans- and cis-EHMC on adult human liver stem cells HL1-hT1 and human-derived lymphoblastoid cells TK-6 using a high-throughput comet assay were studied. TK-6 cells treated with cis-EHMC showed a high level of DNA damage when compared to untreated cells in concentrations 1.56 to 25μgmL^-1. trans-EHMC showed genotoxicity after exposure to the two highest concentrations 12.5 and 25μgmL^-1. The increase in DNA damage on HL1-hT1 cells induced by cis-EHMC and trans-EHMC was detected at the concentration 25μgmL^-1. The No observed adverse effect level (NOAEL, mg kg^-1bwday^-1) was determined using a Quantitative in vitro to in vivo extrapolation (QIVIVE) approach: NOAEL_trans-EHMC=3.07, NOAEL_cis-EHMC=0.30 for TK-6 and NOAEL_trans-EHMC=26.46, NOAEL_cis-EHMC=20.36 for HL1-hT1. The hazard index (HI) was evaluated by comparing the reference dose (RfD, mgkg^-1bwday^-1) obtained from our experimental data with the chronic daily intake (CDI) of the female population. Using comet assay experimental data with the more sensitive TK-6 cells, HI_cis-EHMC was 7 times higher than HI_trans-EHMC. In terms of CDI, relative contributions were; dermal exposure route>oral>inhalation. According to our results we recommend the RfD_trans-EHMC=0.20 and RfD_cis-EHMC=0.02 for trans-EHMC and cis-EHMC, respectively, to use for human health risk assessment. The significant difference in trans-EHMC and cis-EHMC response points to the need for toxicological reevaluation and application reassessment of both isomers in PCPs.

Protective microencapsulation of β-lapachone using porous glass membrane technique based on experimental optimisation

Even though β-lapachone is a novel drug with pharmacological activity, it has limitations including instability under light conditions. The main purpose of the study was to enhance the stability of β-lapachone using the microencapsulation method. The Shirasu porous glass membrane was used to achieve uniform-sized microcapsules. The prepared microcapsules were evaluated to investigate how process parameters affect the encapsulation efficiency, photostability and particle size distribution. The experimental design was conducted to obtain optimal formulations. In addition, an operating space was drawn to identify the safer range of control factors. All control factors showed significant effects on the encapsulation efficiency and photostability. For example, when a large amount of polymers was used, encapsulation efficiency and photostability were improved. However, as the amount of polymers increased, large and polydisperse microcapsules were produced. The robust design method provided information to characterise significant factors, thereby allowing effective control of photostability and size of microcapsules.

Nanoparticles and nanofibers for topical drug delivery

This review provides the first comprehensive overview of the use of both nanoparticles and nanofibers for topical drug delivery. Researchers have explored the use of nanotechnology, specifically nanoparticles and nanofibers, as drug delivery systems for topical and transdermal applications. This approach employs increased drug concentration in the carrier, in order to increase drug flux into and through the skin. Both nanoparticles and nanofibers can be used to deliver hydrophobic and hydrophilic drugs and are capable of controlled release for a prolonged period of time. The examples presented provide significant evidence that this area of research has - and will continue to have - a profound impact on both clinical outcomes and the development of new products.

Edible coatings as encapsulating matrices for bioactive compounds: a review

Edible coatings can extend the shelf-life of many foods, controlling moisture and solute migration, gas exchange and oxidative reaction rates. Besides, edible coatings can be used as carriers of bioactive compounds to improve the quality of food products such as antioxidants, antimicrobials, flavors and probiotics. These approaches can be useful to extend shelf-life as well as provide a functional product. When edible coatings are used as a matrix holding bioactive compounds remarkable benefits arise; off odors and flavors can be masked, bioactive compounds are protected from the environment, and controlled release is allowed. In this sense, the present review will be focused on analyzing the potential use of encapsulation with edible coatings to incorporate bioactive compounds, solving the disadvantages of direct application.

Lipid nanoparticles as novel delivery systems for cosmetics and dermal pharmaceuticals

INTRODUCTION

Lipid nanoparticles are innovative carrier systems developed as an alternative to traditional vehicles such as emulsions, liposomes and polymeric nanoparticles. Solid lipid nanoparticles (SLN) and the newest nanostructured lipid carriers (NLC) show important advantages for dermal application of cosmetics and pharmaceuticals.

AREA COVERED

This article focuses on the main features of lipid nanoparticles, in terms of their preparation and recent advancements. A detailed review of the literature is presented, introducing the importance of these systems in the topical delivery of drugs and active substances.

EXPERT OPINION

Lipid nanoparticles are able to enhance drug penetration into the skin, allowing increased targeting to the epidermis and consequently increasing treatment efficiency and reducing the systemic absorption of drugs and cosmetic actives. The complete biodegradation of lipid nanoparticles and their biocompatible chemical nature have secured them the title of 'nanosafe carriers.' SLN and NLC represent a new technological era, which has been taken over by the cosmetic and pharmaceutical industry, which will open new channels for effective topical delivery of substances.

Nanoparticles in dermatology

Recent advances in the field of nanotechnology have allowed the manufacturing of elaborated nanometer-sized particles for various biomedical applications. A broad spectrum of particles, extending from various lipid nanostructures such as liposomes and solid lipid nanoparticles, to metal, nanocrystalline and polymer particles have already been tested as drug delivery systems in different animal models with remarkable results, promising an extensive commercialization in the coming years. Controlled drug release to skin and skin appendages, targeting of hair follicle-specific cell populations, transcutaneous vaccination and transdermal gene therapy are only a few of these new applications. Carrier systems of the new generation take advantage of improved skin penetration properties, depot effect with sustained drug release and of surface functionalization (e.g., the binding to specific ligands) allowing specific cellular and subcellular targeting. Drug delivery to skin by means of microparticles and nanocarriers could revolutionize the treatment of several skin disorders. However, the toxicological and environmental safety of micro- and nanoparticles has to be evaluated using specific toxicological studies prior to a wider implementation of the new technology. This review aims to give an overview of the most investigated applications of transcutaneously applied particle-based formulations in the fields of cosmetics and dermatology.