Azelaic acid-loaded nanoemulsion with hyaluronic acid – a new strategy to treat hyperpigmentary skin disorders

Azelaic acid-based lyotropic liquid crystals gel for acne vulgaris: Formulation optimization, antimicrobial activity and dermatopharmacokinetic study

The proposed study aimed to develop a topical gel containing azelaic acid (AZA)-based lyotropic liquid crystals (LLCs) for the treatment of acne vulgaris. AZA-based LLCs were optimized by varying Poloxamer-407 and polyvinyl alcohol concentration using a central composite design, which showed that both independent variables had a significant effect on the formulation. The highest desirable trial of AZA-based LLCs (Batch-7) containing 300 mg poloxamer-407 and 100 mg polyvinyl alcohol depicted the particle size, zeta potential, and entrapment efficiency of 184.2 nm, -16.1 mV, and 79.96 %, respectively. TEM images confirmed the globular vesicles of LLCs, and ATR-FTIR and DSC results confirmed the compatibility of formulation excipients. In vitro, the release of AZA, AZA-based LLCs, AZA-based LLC gel, and marketed gel showed a release of 23.29, 95.24, 91.07 and 59.88 %, respectively, after 24 h in phosphate buffer pH 6.8. Ex vivo release of AZA-based LLC gel displayed an 86.56 % release after 24 h. The antimicrobial activity of AZA-based LLC gel exhibited a comparable efficacy with marketed gel against Cutibacterium acnes, Staphylococcus epidermis and Staphylococcus aureus. The acute dermal irritation study indicated excellent safety and skin compatibility of AZA-based LLC gel without any erythema and edema. The dermatopharmacokinetic study displayed an enhanced drug retention for AZA-based LLC gel (146.121 ± 21.13 µg/cm2) than marketed gel (58.58 ± 15.95 µg/cm2) in the dermal layer, which would improve its therapeutic effect. These outcomes proved that AZA-based LLC gel has the potential to enhance skin penetration and retention for effective management of acne vulgaris.

Nano-vesicular systems for melanocytes targeting and melasma treatment: In-vitro characterization, ex-vivo skin retention, and preliminary clinical appraisal

Melasma represents an acquired melanogenesis disorder resulting in skin's hyperpigmentation effect. Although several approaches are adopted for melasma treatment, nanotechnology presents the most convenient one. Therefore, the present work aimed to formulate and characterize three nano-vesicular systems namely, liposomes, penetration enhancer containing vesicles (PEVs) and invasomes to enhance the topical delivery of the skin whitening agent; alpha arbutin (α-arbutin) for the treatment of melasma. Liposomes were prepared according to a 23 full factorial design and the selected formula was further employed for the preparation of PEVs and invasomes. Results showed that the three vesicular systems exhibited nano-sizes ranging from 151.95 to 672.5 nm, negative charges ranging from -12.50 to -28.20 mV, high entrapment efficiencies ranging from 80.59 to 99.53 %, good stability and prolonged-release of α-arbutin for 24 h after dispersion in hydrogel form. The deposition study from the vesicular hydrogel confirmed their effectiveness for the drug's accumulation in the skin reaching an average of 1.6-fold higher in the stratum corneum, 1.6-1.8-fold higher in the epidermis, and 1.6-1.8-fold higher in the dermis compared to the free drug dispersion in hydrogel. A preliminary clinical split-face study on patients suffering from melasma revealed that α-arbutin-loaded liposomes and PEVs in hydrogel forms showed better clinical outcomes compared to the free α-arbutin hydrogel as well as to the previously published α-arbutin encapsulated in chitosan nanoparticles and dispersed in hydrogel form. This delineates the aforementioned nano-vesicular systems as effective and clinically superior delivery means for melasma management.

Development and evaluation of methotrexate-loaded nanoemulsion formulation for topical treatment of psoriasis

Psoriasis is a chronic inflammatory disease that is becoming widespread and is associated with many kinds of additional severe diseases. The present study aimed to develop a methotrexate-loaded almond oil-based nanoemulsion formulation (MTX NE) for topical administration. The drug-loaded nanoemulsion formulation was prepared by high shear homogenization technique. The formulation's stability, as well as other physical and chemical characteristics, including entrapment effectiveness, drug release kinetics, skin permeability, skin irritation, and in vivo evaluation of the optimized formulation, was assessed. Additionally, imiquimod-induced psoriasis in rats was employed to investigate the efficacy of MTX NE against skin disorders. The MTX NE formulation was developed with a particle size of 18.74 ± 9.748 nm, a polydispersity index (PDI) of 0.198 ± 0.01, and an average entrapment efficiency of 79.65 ± 3.84%. The release kinetics model estimates 81.08% drug release at pH 5.5 after 24 h. The major layers of the skin, the epidermis, and dermis were successfully fluidized by the optimized MTX NE formulation, as shown by FTIR results, most likely enhancing drug retention and permeability. However, since Tween 80 and PEG 400 are well-known penetration enhancers, their application greatly accelerates these effects. Permeation data indicate that after 24 h, methotrexate was released from the nano-emulsion at 76.83 ± 4.98 g/cm2 with a flux rate of 2.385 ± 0.61 µg/cm2/h. The in vivo study conducted on rabbit skin showed that the enhanced skin penetration of the prepared MTX-loaded nanoemulsion formulation does not cause any structural modifications in the inter-cellular lipid layers of the stratum corneum. Rabbits used in the in vivo anti-psoriatic investigation demonstrated that MTX NE produced a 95% reduction in PASI. The pharmacokinetic profile revealed that the Cmax, Tmax, and t1/2 values were 8.63 µg/mL, 12.5 h, and 17.77 ± 2.21 h, respectively. These findings suggest that the formulation MTX NE is effective in treating psoriasis and may reduce psoriasis symptoms.

Hyaluronic acid as a tumor progression agent and a potential chemotherapeutic biomolecule against cancer: A review on its dual role

Hyaluronic acid is a major constituent of the extracellular matrix of vertebrate tissue that provides mechanical support to cells and acts as a mediator in regulation of necessary biochemical process essential for maintenance of tissue homeostasis. The variation in quantity of hyaluronic acid content in tissues is often associated with different pathological conditions. It is associated with tumor aggression and progression as it plays crucial role in regulating different aspects of tumorigenesis and several defined hallmarks of cancer. It assists in tumor progression by undergoing extracellular remodeling to establish tumor microenvironment which restricts the delivery of cytotoxic drugs to neoplastic cells due to increase in interstitial pressure. Hyaluronic acid catabolic and anabolic genes and low-molecular weight hyaluronic acid play significant role in the establishing tumor microenvironment by assisting in cell proliferation, metastasis and invasion. On the other hand, it is also used as an effective drug-delivery platform in cancer therapies as its biocompatibility and biodegradability lower the toxicity of chemotherapeutic drugs and increase drug retention. High-molecular weight hyaluronic acid-bioconjugates specifically bind with hyaladherins, facilitating targeted drug delivery and also exert anti-inflammatory properties. This review also highlights the market and patent trends in the development of effective chemotherapeutic hyaluronic acid formulations and the current scenario regarding clinical trials.

Mechanism, Formulation, and Efficacy Evaluation of Natural Products for Skin Pigmentation Treatment

Skin pigmentation typically arises from the excessive secretion and accumulation of melanin, resulting in a darker complexion compared to normal skin. Currently, the local application of chemical drugs is a first-line strategy for pigmentation disorders, but the safety and efficacy of drugs still cannot meet clinical treatment needs. For long-term and safe medication, researchers have paid attention to natural products with higher biocompatibility. This article begins by examining the pathogenesis and treatment approaches of skin pigmentation diseases and summarizes the research progress and mechanism of natural products with lightening or whitening effects that are clinically common or experimentally proven. Moreover, we outline the novel formulations of natural products in treating pigmentation disorders, including liposomes, nanoparticles, microemulsions, microneedles, and tocosomes. Finally, the pharmacodynamic evaluation methods in the study of pigmentation disorder were first systematically analyzed. In brief, this review aims to collect natural products for skin pigmentation treatment and investigate their formulation design and efficacy evaluation to provide insights for the development of new products for this complex skin disease.

Nanosystems with potential application as carriers for skin depigmenting actives

Hyperpigmentation is a skin disorder characterized by excessive production of melanin in the skin and includes dyschromias such as post-inflammatory hyperchromias, lentigens, melasma and chloasma. Topical products containing depigmenting agents offer a less aggressive treatment option for hyperpigmentation compared to methods like chemical peels and laser sessions. However, some of these agents can cause side effects such as redness and skin irritation. Encapsulating these actives in nanosystems shows promise in mitigating these effects and improving product safety and efficacy. In addition, nanocarriers have the ability to penetrate the skin, potentially allowing for targeted delivery of actives to the affected areas. The most commonly investigated nanosystems are nanoemulsions, vesicular nanosystems and nanoparticles, in which different materials can be used to generate different compositions in order to improve the properties of these nanocarriers. Nanocarriers have already been widely explored, but it is necessary to understand the evolution of these technologies when applied to the treatment of skin hyperchromias. Therefore, this literature review aims to present the state of the art over the last 15 years on the use of nanosystems as a potential strategy for encapsulating depigmenting actives for potential application in cosmetic products for skin hyperchromia. By providing a comprehensive overview of the latest research findings and technological advances, this article can contribute to improving the care and quality of life of people affected by this skin condition.

New insights into the anti-inflammatory and anti-melanoma mechanisms of action of azelaic acid and other Fusarium solani metabolites via in vitro and in silico studies

Metabolites exploration of the ethyl acetate extract of Fusarium solani culture broth that was isolated from Euphorbia tirucalli root afforded five compounds; 4-hydroxybenzaldehyde (1), 4-hydroxybenzoic acid (2), tyrosol (3), azelaic acid (4), malic acid (5), and fusaric acid (6). Fungal extract as well as its metabolites were evaluated for their anti-inflammatory and anti-hyperpigmentation potential via in vitro cyclooxygenases and tyrosinase inhibition assays, respectively. Azelaic acid (4) exhibited powerful and selective COX-2 inhibition followed by fusaric acid (6) with IC50 values (2.21 ± 0.06 and 4.81 ± 0.14 μM, respectively). As well, azelaic acid (4) had the most impressive tyrosinase inhibitory effect with IC50 value of 8.75 ± 0.18 μM compared to kojic acid (IC50 = 9.27 ± 0.19 μM). Exclusive computational studies of azelaic acid and fusaric acid with COX-2 were in good accord with the in vitro results. Interestingly, this is the first time to investigate and report the potential of compounds 3-6 to inhibit cyclooxygenase enzymes. One of the most invasive forms of skin cancer is melanoma, a molecular docking study using a set of enzymes related to melanoma suggested pirin to be therapeutic target for azelaic acid and fusaric acid as a plausible mechanism for their anti-melanoma activity.

Different therapeutic approaches in melasma: advances and limitations

Melasma is a chronic hyperpigmentation skin disorder that is more common in the female gender. Although melasma is a multifactorial skin disorder, however, sun-exposure and genetic predisposition are considered as the main etiologic factors in melasma occurrence. Although numerous topical and systemic therapeutic agents and also non-pharmacologic procedural treatments have been considered in melasma management, however, the commonly available therapeutic options have several limitations including the lack of sufficient clinical effectiveness, risk of relapse, and high rate of unwanted adverse drug reactions. Recruitment of nanotechnology for topical drug delivery in melasma management can lead to enhanced skin penetration, targeted drug delivery to the site of action, longer deposition at the targeted area, and limit systemic absorption and therefore systemic availability and adverse drug reactions. In the current review, first of all, the etiology, pathophysiology, and severity classification of melasma have been considered. Then, various pharmacologic and procedural therapeutic options in melasma treatment have been discussed. Afterward, the usage of various types of nanoparticles for the purpose of topical drug delivery for melasma management was considered. In the end, numerous clinical studies and controlled clinical trials on the assessment of the effectiveness of these novel topical formulations in melasma management are summarized.

Drug permeation enhancement, efficacy, and safety assessment of azelaic acid loaded SNEDDS hydrogel to overcome the treatment barriers of atopic dermatitis

Atopic dermatitis is one of the most widespread chronic inflammatory skin conditions that can occur at any age, though the prevalence is highest in children. The purpose of the current study was to prepare and optimize the azelaic acid (AzA) loaded SNEDDS using Pseudo ternary phase diagram, which was subsequently incorporated into the Carbopol 940 hydrogel for the treatment of atopic dermatitis. The composition was evaluated for size, entrapment efficiency, in vitro, ex vivo, and in vivo studies. The polydispersity index of the optimized preparation was found to be less than 0.5, and the size of the distributed globules was found to be 151.20 ± 3.67 nm. The SNEDDS hydrogel was characterized for pH, viscosity, spreadability, and texture analysis. When compared to the marketed formulation, SNEDDS hydrogel was found to have a higher rate of permeation through the rat skin. In addition, a skin irritation test carried out on experimental animals showed that the SNEDDS formulation did not exhibit any erythematous symptoms after a 24-h exposure. In conclusion, the topical delivery of AzA through the skin using SNEDDS hydrogel could prove to be an effective approach for the treatment of atopic dermatitis.

Identification and molecular mechanism of novel 5-alkenyl-2-benzylaminothiazol-4(5H)-one analogs as anti-melanogenic and antioxidant agents

Mushroom tyrosinase is a tetramer, whereas mammalian tyrosinase is a monomeric glycoprotein. In addition, the amino acid sequence of mushroom tyrosinases differs from that of mammalian tyrosinases. MHY2081 exhibits potent inhibitory activity against both mushroom and mammalian tyrosinases. Accordingly, based on the MHY2081 structure, 5-alkenyl-2-benzylaminothiazol-4(5H)-one analogs were designed as a novel anti-tyrosinase agent and synthesized using 2-((3,4-dimethoxybenzyl)amino)thiazol-4(5H)-one (16), a key intermediate obtained via the rearrangement of a benzylamino group. Compounds 6 and 9 (IC50 = 1.5-4.6 µM) exhibited higher mushroom tyrosinase inhibitory activity than kojic acid (IC50 = 20-21 µM) in the presence of l-tyrosine and/or l-dopa. Based on kinetic analysis using Lineweaver-Burk plots, 6 was a mixed inhibitor, whereas 9 was a competitive inhibitor, and docking simulation results supported that these compounds could bind to the active site of mushroom tyrosinase. Using B16F10 mammalian cells, we demonstrated that these compounds inhibited melanogenesis more potently than kojic acid, and their anti-melanogenic effects could be attributed to tyrosinase inhibition. All synthesized compounds could scavenge reactive oxygen species (ROS), with five compounds exhibiting mild-to-strong ABTS+ and DPPH radical-scavenging abilities. Compounds 6 and 9 were potent tyrosinase inhibitors with strong antioxidant activities against ROS, ABTS+, and DPPH radicals. Moreover, the compounds significantly suppressed tyrosinase expression in a dose-dependent manner. Collectively, these results suggest that the novel 5-alkenyl-2-benzylaminothiazol-4(5H)-one analogs, especially 6 and 9, are potential anti-melanogenic agents with antioxidant activity.

Biomolecular interactions and binding dynamics of inhibitor arachidonic acid, with tyrosinase enzyme

Hyperpigmentation is a disorder caused by increased melanin deposition and changes in skin pigmentation. Inhibition of tyrosinase activity contributes to the control of food browning and skin pigmentation diseases. The effects of arachidonic acid (AA) on tyrosinase activity were examined using different spectroscopy methods including UV-VIS spectrophotometry, fluorescence spectroscopy, circular dichroism (CD) differential scanning calorimetry, and molecular dynamics (MD) simulations. Based on the kinetic results, arachidonic acid showed mixed-type of inhibition with Ki = 4.7 µM. Fluorescence and CD studies showed changes of secondary and tertiary structures of enzyme and a reduction of α-helix* amino acids after its incubation with different concentrations of AA, which is also confirmed by DSSP analysis. In addition, differential scanning calorimetry (DSC) studies showed a decrease in thermodynamic stability of enzyme from Tm = 338.65k for sole enzyme after incubation with AA in comparison with complex enzyme with Tm= 334.26k, ΔH =7.52 kJ/mol, and ΔS = 0.15 kJ/mol k. Based on the theoretical methods, it was found that the interaction between enzyme and AA follows an electrostatic manner with ΔG = -8.314 kJ/mol and ΔH = -12.9 kJ/mol. The MD results showed the lowest flexibility in the complex amino acids and minimal fluctuations in AA interaction with tyrosinase in Residue 240 to 260 and 66 to 80. Thus, AA inhibitory and structural and thermodynamic instability of tyrosinase supported advantages of this fatty acid for prevention of medical hyperpigmentation. Therefore, it is a good candidate for cosmetic applications. Communicated by Ramaswamy H. Sarma.

Development of a Clioquinol Nanocarrier as a New, Promising Option for the Treatment of Dermatomycosis

Dermatomycosis is a common fungal infection, and its treatment is limited by few antifungal agents. Clioquinol (CQ) is an antiparasitic agent that has been studied for new uses, such as antifungal and antiviral applications. CQ was incorporated into a lipid-based nanocarrier as a new, promising option for dermatomycosis. This study aimed to develop a CQ-loaded lipid-based nanocarrier for cutaneous application and to evaluate its antifungal activity. CQ-loaded nanoformulation (LBN-CQ) was developed using the ultrasonication method, and the particle size, polydispersity index (PDI), pH, zeta potential, and drug content were monitored for 45 days. To evaluate antifungal activity, broth microdilution and a time-kill assay were performed. LBN-CQ presented a particle size of 91 ± 3 nm and PDI of 0.102 ± 0.009. The zeta potential and pH values were -9.7 ± 2.0 mV and 6.0 ± 0.1, respectively. The drug content was 96.4 ± 2.3%, and the encapsulation efficiency was 98.4%. LBN-CQ was able to reduce the minimum inhibitory concentration (MIC) in a 2-fold or 4-fold manner in most of the tested strains. Additionally, LBN-CQ presented stable fungistatic action that was not concentration- or time-dependent. In conclusion, the developed CQ-loaded nanocarrier is a promising treatment for skin fungal infections and a promising candidate for future randomized clinical trials.

Nanoemulsion Containing Kojic Dipalmitate and Rosehip Oil: A Promising Formulation to Treat Melasma

Melasma is a hard-to-treat hyperpigmentation disorder. Combined incorporation of kojic dipalmitate (KDP), the esterified form of kojic acid, and rosehip oil, an oil with antioxidant and skin-regenerating properties, into nanocarrier systems appears to be a suitable strategy to develop high-performance formulations. A high-energy method (Ultra-Turrax^®) was used to develop nanoemulsions containing up to 2 mg/mL KDP, 5% rosehip oil, and 7.5% surfactant. Formulations were characterized regarding droplet size, size distribution, pH, density, morphology, KDP content, incorporation efficiency, and stability under different temperature conditions. A scale-up study was conducted. Skin permeation, antioxidant potential, and tyrosinase inhibitory activity were assessed in vitro. Cell viability studies were also performed. Results showed that nanoemulsions containing 1 and 2 mg/mL KDP had incorporation efficiencies greater than 95%, droplet size smaller than 130 nm, suitable size distribution, zeta potential of approximately -10 mV, and good stability over 30 days of refrigerated storage. The nanoemulsion containing 1 mg/mL KDP was chosen for further evaluation because it had lower nanocrystal formation, greater scale-up feasibility and allowed KDP permeation up to the epidermis similarly than observed for 2 mg/mL KDP. This formulation (1 mg/mL KDP) showed antioxidant and depigmenting efficacy, close to that of 1 mM ascorbic acid. No cytotoxicity was observed in formulations concentrations ranging from 0.06% to 1%.

The Impact of Interpretive Packaged Food Labels on Consumer Purchase Intention: The Comparative Analysis of Efficacy and Inefficiency of Food Labels

The objectives of this study are twofold. Firstly, the current study elucidates the impact and efficacy of food labels in developing consumers' attitudes and intentions towards the selection of nutritional food. Secondly, the inefficacy of labels in developing consumers' attitudes and intentions towards healthy packaged food selection is demonstrated. The supportive theories of the current model are those of reasoned action and protection motivation. The data of 797 respondents have been collected from four major grocery stores in Pakistan. The structural equation model has been employed for the analysis of data. The results indicate that the efficacy of food labels has a positive significant effect on attitudes towards familiar and unfamiliar foods. In contrast to this, inefficacy in labelling has shown a positive significant effect on familiar foods but is insignificant for unfamiliar foods. The user-friendly food labels significantly affect unfamiliar foods in terms promoting consumer attitudes. Reciprocally, the inefficacy of labels creates a hindrance to the reading of unfamiliar labels while purchasing food items. The study findings reveal the fact that food label information and its format influences consumer attitudes and intentions at the point of purchase.

Combining Topical and Oral Botanicals for Skin Redness, Pigmentation, Sleep, and Mood: A Randomized Controlled Study

External and internal stressors have been found to adversely affect skin health and overall wellness. There is growing interest in the use of anti-inflammatory and antioxidant plant-derived ingredients, such as ashwagandha, saffron, l-theanine, and tocopherol, to mitigate the impact of these stressors. In this study, we evaluate the effectiveness of oral and topical products (InnerCalm and SuperCalm, respectively) that contain naturally derived ingredients on skin redness, skin pigmentation, sleep, and mood in healthy females with Fitzpatrick skin type 1−4 and self-perceived sensitive skin. Subjects were randomized to an oral (oral group), a topical (topical group), or a combination of both the oral and topical interventions (combined group). Standardized photography-based image analysis was used to assess skin redness and pigment. Self-assessments of mood and sleep were measured with the abbreviated profile of mood states (POMS) questionnaire, and the Pittsburgh sleep-quality index (PSQI), respectively. Assessments were made at the baseline, 1-week, 4-weeks, and 8-weeks of the intervention. The average facial redness decreased in the topical group at 8-weeks (p < 0.001) and in the combined group at 4-weeks (p < 0.05) and 8-weeks (p < 0.001), relative to the baseline. The average facial pigmentation decreased in the oral (p < 0.05) and combined (p < 0.05) cohorts at 8-weeks, relative to the baseline. The oral group exhibited an improvement in sleep quality at 1-week relative to the baseline (p < 0.05) and at 8-weeks relative to the baseline (p < 0.05). Finally, the combined group demonstrated improvement in fatigue (p < 0.01) and confusion (p < 0.05) at 8-weeks relative to the baseline, though total mood disturbance increased in all 3 groups over the course of the study. Measured outcomes relating to mood may be confounded with the timing of the study, which ran during the COVID pandemic. Overall, we demonstrate the role of oral and topical herbs and of nutraceuticals for skin health and wellness. Further research will be needed to elucidate synergistic effects in oral and topical combination regimens.

Recent Advances of Hyaluronan for Skin Delivery: From Structure to Fabrication Strategies and Applications

Hyaluronan (HA) plays a fundamental role in maintaining the homeostasis on skin health. Furthermore, the effect of HA in skin inflammatory diseases is worth studying in the next future. HA and its conjugates change the solubility of active pharmaceutical ingredients, improve emulsion properties, prolong stability, reduce immunogenicity, and provide targeting. HA penetrates to deeper layers of the skin via several mechanisms, which depend on the macromolecular structure and composition of the formulation. The cellular and molecular mechanisms involved in epidermal dysfunction and skin aging are not well understood. Nevertheless, HA is known to selectively activate CD44-mediated keratinocyte signaling that regulates its proliferation, migration, and differentiation. The molecular size of HA is critical for molecular mechanisms and interactions with receptors. High molecular weight HA is used in emulsions and low molecular weight is used to form nanostructured lipid carriers, polymeric micelles, bioconjugates, and nanoparticles. In the fabrication of microneedles, HA is combined with other polymers to enhance mechanical properties for piercing the skin. Hence, this review aims to provide an overview of the current state of the art and last reported ways of processing, and applications in skin drug delivery, which will advocate for their broadened use in the future.

Optimization of Experimental Procedure for Determining Azelaic Acid in Cosmetics by Gas Chromatography Derivatized through Ethanol

The quantitative evaluation of azelaic acid is becoming critical in the development of new medicinal products and in environment. A feasible method for the determination of azelaic acid in cosmetics by gas chromatographic-mass spectrometer detector (GC-MS) with derivation was developed and optimized. The derivative effect was good, when azelaic acid was derivatized through ethanol at room temperature for 10 min with 800 μL of sulfuric acid as a catalyst. A good linear relationship of azelaic acid derivative was present from 10 to 1000 mg L^-1 (R ² = 0.9997). Detection limit and quantitative limit of GC was 15 and 50 mg kg^-1, respectively. The recovery rate was in the range from 87.7% to 101% with all relative standard deviation (RSD) values less than 4%, denoting the method meeting the requirement of the analysis. Therefore, this method has the advantages of strong anti-interference ability and accurate results. Among the eight samples nominally azelaic acid, only three were detected. The respective content was 78 133, 16 710, and 2431 mg kg^-1. The results showed that the actual addition of the azelaic acid in the market was quite different with label identification, being worthy of further attention. Further, it also provided a favorable experience for the monitoring of azelaic acid in the environment.

Functionalized chitosan nanoparticles for cutaneous delivery of a skin whitening agent: an approach to clinically augment the therapeutic efficacy for melasma treatment

The increase in the production of melanin level inside the skin prompts a patient-inconvenient skin color disorder namely; melasma. This arouses the need to develop efficacious treatment modalities, among which are topical nano-delivery systems. This study aimed to formulate functionalized chitosan nanoparticles (CSNPs) in gel form for enhanced topical delivery of alpha-arbutin as a skin whitening agent to treat melasma. Ionic gelation method was employed to prepare α-arbutin-CSNPs utilizing a 2⁴ full factorial design followed by In vitro, Ex vivo and clinical evaluation of the nano-dispersions and their gel forms. Results revealed that the obtained CSNPs were in the nanometer range with positive zeta potential, high entrapment efficiency, good stability characteristics and exhibited sustained release of α-arbutin over 24 h. Ex vivo deposition of CSNPs proved their superiority in accumulating the drug in deep skin layers with no transdermal delivery. DSC and FTIR studies revealed the successful amorphization of α-arbutin into the nanoparticulate system with no interaction between the drug and the carrier system. The comparative split-face clinical study revealed that α-arbutin loaded CSNPs hydrogels showed better therapeutic efficacy compared to the free drug hydrogel in melasma patients, as displayed by the decrease in: modified melasma area and severity index (mMASI) scores, epidermal melanin particle size surface area (MPSA) and the number of epidermal monoclonal mouse anti–melanoma antigen recognized by T cells-1 (MART-1) positive cells which proved that the aforementioned system is a promising modality for melasma treatment.

Features, applications, and sustainability of lipid nanoparticles in cosmeceuticals

Cosmeceuticals are a branch of cosmetic products that forms a bridge between cosmetic and drug products. It is a fast-growing branch of the cosmetic industry, especially after the introduction of novel formulation and manufacturing techniques such as lipid nanoparticles (LNPs). These LNPs-based cosmeceutical products offer several advantages such as enhanced bioavailability of cosmeceutical active ingredients (CAIs), improved aesthetic appeal, and stability of the final products. However, the use of these LNPs may raise some concerns about possible side effects of these LNPs and potential hazards to the customer's health. Accordingly, an update that focuses on the use of this important branch of nanoparticles is necessary since most review papers are dealing with all types of nanocarriers in the same review with little focus on LNPs. Therefore, in the current review, a detailed analysis of the advantages and disadvantages of LNPs in this field was highlighted, to emphasize the LNPs-based cosmeceuticals on the market, as well as the potential risk posed by LNPs on exposure and recently introduced regulatory guidelines to address them. In addition, if these products can be a candidate as products that meet the sustainable development goals raised by the UN are discussed.

Recent exploration of nanoemulsions for drugs and cosmeceuticals delivery

BACKGROUND

Nanoemulsions (NEs) have been explored as nanocarriers for the delivery of many drugs and cosmeceuticals. The extraordinary expansion of using NEs is due to their capability to conquer the main challenges of conventional delivery systems such as short residence time with low patient acceptance, poor stability, low aqueous solubility, permeability, and hence bioavailability.

METHODS

This review recapitulated the most recent pharmaceutical and cosmeceutical applications of NEs as effective delivery nanocarriers. The outputs of our research studies and the literature review on the latest NEs applications were assessed to highlight the NEs components, preparations, applications, and the improved quality and elegance of the used product.

RESULTS

NEs are stable submicronic translucent dispersions with narrow droplet size distribution. They exhibited excellent ability to efficiently encapsulate therapeutics of diverse nature of drugs and cosmeceuticals. NE formulations showed superiority over conventional delivery approaches with overabundances of advantages through different routes of administration. This novel technology exhibited better aesthetic appeal, higher bioavailability, and a longer duration compared to the conventional delivery systems.

CONCLUSION

This novel technology holds promise for different therapeutics fields. However, the success of NEs use advocated the development of robust formulations, proper choice of equipment, ample process characterization, and assurance of their efficacy, stability, safety and cosmetic appeal.

Azelaic acid and Melaleuca alternifolia essential oil co-loaded vesicular carrier for combinational therapy of acne

Aim: Azelaic acid (AzA), a comedolytic, antibacterial, anti-inflammatory anti-melanogenic agent, prescribed against acne vulgaris is safe on skin. Its combination with another widely used anti-acne agent, tea tree oil (EO) whose delivery is limited by volatility, instability and lipophilicity constraints was attempted. Method: Solvent injection was used to prepare AzA-EO integrated ethosomes. Result: Ethosomes were transformed into carbopol hydrogel, which exhibited pseudo-plastic properties with appreciable firmness, work of shear, stickiness and work of adhesion. The hydrogel showed better permeation and retention characteristics vis-a-vis commercial formulation (AzidermTM), when evaluated in Wistar rat skin. Further, ethosome hydrogel composite was better tolerated with no side effects. Conclusion: The findings suggests that the aforementioned strategy could be a potential treatment used for acne management.

Hydrogel composite containing azelaic acid and tea tree essential oil as a therapeutic strategy for Propionibacterium and testosterone-induced acne

Azelaic acid (AzA) is a USFDA bioactive prescribed against acne vulgaris. It possesses delivery challenges like poor aqueous solubility, low skin-penetrability, and dose-dependent side effects, which could be overcome by its synergistic combination with tea tree oil (TTO) as a microemulsion (ME)-based hydrogel composite. AzA-TTO ME was prepared to employ pseudo-ternary phase diagram construction. The best AzA-TTO ME was of uniform size (polydispersity index < 0.7), nano-range (~357.4 ± 2% nm), transmittance (> 90%), and negative zeta potential (−1.42 ± 0.25% mV) values. ME hydrogel composite with optimum rheological and textural attributes showed better permeation, retention, and skin-compliant characteristics, vis-a-vis marketed formulation (Aziderm™) when evaluated in Wistar rat skin. In vitro antibacterial efficacy in bacterial strains, i.e., Staphylococcus aureus, Propionibacterium acne, and Staphylococcus epidermidis, was evaluated employing agar well plate diffusion and broth dilution assay. ME hydrogel has shown an increase in zone of inhibition by two folds and a decrease in minimum inhibitory concentration (MIC) by eightfold against P. acnes vis-a-vis AzA. Finally, ME hydrogel composite exhibited a better reduction in the papule density (93.75 ± 1.64%) in comparison to Aziderm™ 72.69 ± 4.67%) on acne as developed in rats by inducing testosterone. Thus, the developed AzA-TTO ME hydrogel composite promises an efficacious and comparatively safer drug delivery system for the topical therapy of acne vulgaris.

Efficacy of hyaluronic acid for recurrent aphthous stomatitis: a systematic review of clinical trials

OBJECTIVES

Recurrent aphthous stomatitis (RAS) is a very common oral mucosal disease, and its management is quite challenging with no definitive cure being available so far. Many studies have tried hyaluronic acid (HA) for alleviating signs and symptoms of RAS. The present systematic review sought to assess the available evidence regarding the efficacy of HA in management of RAS.

METHODS

Two reviewers independently conducted extensive search in four online databases (PubMed, Scopus, Web of Science, and Google Scholar) and the gray literature, with no restriction to date or language of the publication. All clinical trials that assessed the efficacy of HA in reducing signs and symptoms of RAS were included. Risk of bias was assessed by two reviewers independently, using the Cochrane assessment tool. Due to substantial heterogeneity, no meta-analysis was feasible.

RESULTS

Out of the 75 identified articles, nine clinical trials involving 538 RAS patients (259 in HA group) were included. The risk of bias was high in five studies, low in one study, and unclear in three studies. The comparative groups varied greatly across the included studies: triamcinolone (in three studies), chlorhexidine mouthwash, lidocaine, placebo, iodine glycerin, diclofenac, and laser therapy. Overall, the results revealed a good efficacy of HA in alleviating pain and shortening the healing time of RAS, without any reported side effects. Compared to triamcinolone, HA showed superior results in one study, and comparable results in two studies.

CONCLUSIONS

The available evidence suggests that HA is a promising treatment option for RAS. However, given the huge heterogeneity of the included studies and high risk of bias in some of these studies, the evidence is inconclusive. Further well-designed clinical trials with standardized methodologies and adequate sample sizes are warranted to discern the efficacy of HA for RAS.

CLINICAL RELEVANCE

Hyaluronic acid might be a viable alternative therapeutic option for patients with RAS.

Recent advances in the design and discovery of synthetic tyrosinase inhibitors

Tyrosinase is a copper-containing metalloenzyme that is responsible for the rate-limiting catalytic step in the melanin biosynthesis and enzymatic browning. As a promising target, tyrosinase inhibitors can be used as skin whitening agents and food preservatives, thus having broad potential in the fields of food, cosmetics, agriculture and medicine. From 2015 to 2020, numerous synthetic inhibitors of tyrosinase have been developed to overcome the challenges of low efficacy and side effects. This review summarizes the enzyme structure and biological functions of tyrosinase and demonstrates the recent advances of synthetic tyrosinase inhibitors from the perspective of medicinal chemistry, providing a better understanding of the catalytic mechanisms and more effective tyrosinase inhibitors.

Nanotechnology-based Drug Delivery Systems as Potential for Skin Application: A Review

Administration of substances through the skin represents a promising alternative, in relation to other drug administration routes, due to its large body surface area, in order to offer ideal and multiple sites for drug administration. In addition, the administration of drugs through the skin avoids the first-pass metabolism, allowing an increase in the bioavailability of drugs, as well as reducing their side effects. However, the stratum corneum (SC) comprises the main barrier of protection against external agents, mainly due to its structure, composition and physicochemical properties, becoming the main limitation for the administration of substances through the skin. In view of the above, pharmaceutical technology has allowed the development of multiple drug delivery systems (DDS), which include liquid crystals (LC), cubosomes, liposomes, polymeric nanoparticles (PNP), nanoemulsions (NE), as well as cyclodextrins (CD) and dendrimers (DND). It appears that the DDS circumvents the problems of drug absorption through the SC layer of the skin, ensuring the release of the drug, as well as optimizing the therapeutic effect locally. This review aims to highlight the DDS that include LC, cubosomes, lipid systems, PNP, as well as CD and DND, to optimize topical skin therapies.

Management of hyperpigmentation: Current treatments and emerging therapies

Hyperpigmentation of the skin refers to a dermatological condition which alters the color of the skin, making it discolored or darkened. The treatments for hyperpigmentation disorders often take very long to show results and have poor patient compliance. The first-line treatment for hyperpigmentation involves topical formulations of conventional agents such as hydroquinone, kojic acid, and glycolic acid followed by oral formulations of therapeutic agents such as tranexamic acid, melatonin, and cysteamine hydrochloride. The second-line approaches include chemical peels and laser therapy given under the observation of expert professionals. However, these therapies pose certain limitations and adverse effects such as erythema, skin peeling, and drying and require long treatment duration to show visible effects. These shortcomings of the conventional treatments provided scope for further research on newer alternatives for managing hyperpigmentation. Some of these therapies include novel formulations such as solid lipid nanocarriers, liposomes, phytochemicals, platelet-rich plasma, microneedling. This review focuses on elaborating on several hyperpigmentation disorders and their mechanisms, the current, novel and emerging treatment options for management of hyperpigmentation.

Recent Advances in Nanomaterials for Dermal and Transdermal Applications

The stratum corneum, the most superficial layer of the skin, protects the body against environmental hazards and presents a highly selective barrier for the passage of drugs and cosmetic products deeper into the skin and across the skin. Nanomaterials can effectively increase the permeation of active molecules across the stratum corneum and enable their penetration into deeper skin layers, often by interacting with the skin and creating the distinct sites with elevated local concentration, acting as reservoirs. The flux of the molecules from these reservoirs can be either limited to the underlying skin layers (for topical drug and cosmeceutical delivery) or extended across all the sublayers of the epidermis to the blood vessels of the dermis (for transdermal delivery). The type of the nanocarrier and the physicochemical nature of the active substance are among the factors that determine the final skin permeation pattern and the stability of the penetrant in the cutaneous environment. The most widely employed types of nanomaterials for dermal and transdermal applications include solid lipid nanoparticles, nanovesicular carriers, microemulsions, nanoemulsions, and polymeric nanoparticles. The recent advances in the area of nanomaterial-assisted dermal and transdermal delivery are highlighted in this review.

Skin Brightening Efficacy of Exosomes Derived from Human Adipose Tissue-Derived Stem/Stromal Cells: A Prospective, Split-Face, Randomized Placebo-Controlled Study

Studies have shown that stem cells and their derivatives, including conditioned media (CM), have inhibitory effects on skin pigmentation. However, evidence supporting the skin brightening effect of exosomes derived from stem cells is lacking. We studied the antipigmentation effect in vitro and skin brightening efficacy in vivo of exosomes derived from human adipose tissue-derived mesenchymal stem/stromal cells (ASC-exosomes). Exosomes were isolated from the CM of ASCs using the tangential flow filtration method. ASC-exosomes reduced intracellular melanin levels in B16F10 melanoma cells regardless of the presence of the α-melanocyte-stimulating hormone (α-MSH). The skin brightening efficacy of a cosmetic formulation containing ASC-exosomes was assessed in human volunteers with hyperpigmentation in a prospective, split-face, double-blind, randomized placebo-controlled study. The ASC-exosome-containing formulation statistically decreased the melanin contents compared to the placebo control. However, the melanin-reduction activity was limited and diminished along with time. A further improvement in efficient transdermal delivery of ASC-exosomes will be helpful for more profound efficacy. In summary, these results suggest that ASC-exosomes can be used as a cosmeceutical for skin brightening.

Synthesis and Technology of Nanoemulsion-Based Pesticide Formulation

Declines in crop yield due to pests and diseases require the development of safe, green and eco-friendly pesticide formulations. A major problem faced by the agricultural industry is the use of conventional agrochemicals that contribute broad-spectrum effects towards the environment and organisms. As a result of this issue, researchers are currently developing various pesticide formulations using different nanotechnology approaches. The progress and opportunities in developing nanoemulsions as carriers for plant protection or nanodelivery systems for agrochemicals in agricultural practice have been the subject of intense research. New unique chemical and biologic properties have resulted in a promising pesticide nanoformulations for crop protection. These innovations-particularly the nanoemulsion-based agrochemicals-are capable of enhancing the solubility of active ingredients, improving agrochemical bioavailability, and improving stability and wettability properties during the application, thus resulting in better efficacy for pest control and treatment. All of these-together with various preparation methods towards a greener and environmentally friendly agrochemicals-are also discussed and summarized in this review.