Squalene Peroxidation and Biophysical Parameters in Acne-Prone Skin: A Pilot "In Vivo" Study.

Nowadays, acne vulgaris therapies are often unsuccessful. One of the responsible factors for the formation of comedones and inflammatory lesions could be the peroxidation of squalene, a hydrocarbon representing one of the major components of human sebum. This peroxidation is increased by solar irradiation. The purpose of this work was to set up an in vivo method for the extraction and quantification of squalene from acne skin and to correlate the results with biophysical skin parameters such as sebum amount, protein content and TEWL. Healthy volunteers were used as control. The results obtained demonstrated that acne-prone skin had a major quantity of squalene, and, in the stratum corneum area, its peroxide form is present. Moreover, Spearman's rank correlation showed a positive correlation between sebum content and peroxide squalene and between porphyrin intensity and peroxide squalene.

In vitro and in vivo efficacy of a cosmetic product formulated with new lipid particles for the treatment of aged skin.

BACKGROUND: The cumulative oxidative damage causes an acceleration in the skin aging. OBJECTIVES: To evaluate the ability of a new patented matrix of lipid particles (SIREN CAPSULE TECHNOLOGY™) to have superior anti-aging properties due to its high sensitivity to reactive oxygen species (ROS), testing its efficacy versus free or encapsulated vitamins. METHODS: An in vitro study was conducted to evaluate the protective effects of lipid particles using menadione as an enhancer of oxidative stress. Subsequently, in vivo studies evaluated skin hydration, skin barrier function, and smoothness and wrinkle depth. For this purpose, gels containing free or encapsulated vitamins were used as controls. RESULTS: In vitro, the SIREN CAPSULE TECHNOLOGY™ gel shows inhibitory activity against ROS production through menadione induction. In fact, at both tested concentrations, ROS production is lower than in the control samples (placebo, free vitamins, encapsulated vitamins). In vivo, the net effect of SIREN CAPSULE TECHNOLOGY™ gel versus the others permitted to conclude that lipid particles exert a higher skin moisturizing effect (20.17%) and a stronger effect in reducing transepidermal water loss (-16.29%) after 4 weeks of treatment. As for surface analysis, a gel based on SIREN CAPSULE TECHNOLOGY™ improves the skin texture in a similar way than gel containing encapsulated vitamins (Ra and Rz variations in 4 weeks). CONCLUSIONS: SIREN CAPSULE TECHNOLOGY™ represents an advance and a successful strategy to develop cosmetic products for the treatment of skin conditions associated with an accumulation of ROS. SIREN CAPSULE TECHNOLOGY™ represents a result-oriented breakthrough in the effective delivery of active ingredients to the skin.

Skin Microbiota: Setting up a Protocol to Evaluate a Correlation between the Microbial Flora and Skin Parameters.

The concept of skin microbiota is not really clear and more accurate approaches are necessary to explain how microbial flora can influence skin biophysical parameters in healthy individuals and in pathology patients with non-infectious skin disease. The aim of this work is to provide a suitable, fast and reproducible protocol to correlate skin parameters with the composition of skin microbiota. For this purpose, the work was split into two main phases. The first phase was focused on the selection of volunteers by the administration of a specific questionnaire. The skin microbiota was then collected from the forehead of selected volunteers as a test area and from the shoulder as control area. On the same skin area, the biophysical parameters, such as trans-epidermal water loss (TEWL), sebum level (SL), porphyrin intensity, keratin content and stratum corneum water content were taken. All parameters were taken at t0 and after 15 days without changes in the volunteers' lifestyle. A strong correlation was found between forehead and shoulder area for porphyrin intensity, pH and TEWL parameters, and between Cutibacterium acnes and some biophysical parameters both in the forehead and the shoulder area. The procedural setup in this work represents the starting point for evaluating problematic skins and the efficacy of cosmetic products or treatment against skin dysbiosis.

Efficacy and safety of a new peeling formulated with a pool of PHAs for the treatment of all skin types, even sensitive.

BACKGROUND: Actually, the use of chemical peels in cosmetics and dermatology continues to grow due to their versatility, clinical endpoint-directed predictability, and favorable risk profile in comparison to lasers. The chemical peel is a generally safe method for treatment of some skin disorders and to refresh and rejuvenate the skin. The major challenge of chemical peels is the tolerability, that is because of sensitive skin which is one of the most common skin disorders. AIM: The aim of this study was to evaluate the effectiveness of the new Miamo Renewal Peel Serum formulated with a pool of new generation acids (ELPA25™) on sensitive skin with respect to mandelic acid serum only and with respect to placebo comparison. MATERIALS AND METHODS: The "in vivo" study following the half-face experimental protocol active versus placebo involved 30 healthy Caucasian female volunteers between 25 and 64 years, with sensitive skin, who were divided into two different groups. ELPA25™ serum was applied in one group three times a week for 8 weeks. The other group, with the same protocol, applied an active serum containing mandelic acid, as control, versus placebo. In particular, skin moisturizing, skin viscoelastic properties, skin surface smoothness, wrinkle reduction, and stratum corneum renewal were evaluated. RESULTS: Renewal Peel Serum was very well tolerated from sensitive skin. A significant decrease in skin roughness and wrinkle breadth, and an improvement in firmness and in skin elasticity, was observed after 2 months of treatment with respect both to mandelic acid serum and to placebo comparison. CONCLUSIONS: Scientific protocol using self-controlled study methodology and noninvasive skin bioengineering techniques with adequate statistical methods were able to evaluate both the safety and the efficacy of the new Miamo Renewal Peel Serum. This study highlighted that the Miamo Renewal Peel Serum formulated with a patent-pending mixture of new generation acids (ELPA25™) exerts many beneficial effects and it can be successfully employed for sensitive skin.

Efficacy of Bovine Nail Membranes as In Vitro Model for Onychomycosis Infected by Trichophyton Species.

Onychomycosis is a fungal infection caused by different etiologic agents, including dermatophytes that specifically colonize keratin-rich substrates. The aim of this work was to investigate mechanical modifications of bovine membranes (used as an in vitro nail model) placed in contact with Trichophyton species. Trichophyton strains were isolated from toenails specimens. The procedure was set up by spreading T. rubrum,T. interdigitale, and T. mentagrophytes strains on Petri dishes with minimal and rich media; after that, bovine membranes were placed in the center. After 27 days, T. interdigitale and T. mentagrophytes significantly reduced the thickness of the colonized membranes, whereas two T. rubrum strains showed the highest degradation limited to the small colonized area. These results were confirmed by SEM images of the colonization profile on membranes. Mechanical analyses performed on membranes were used as an innovative method to evaluate the thickness and structural integrity of membranes variation following fungal colonization. In conclusion, mechanical analyses of substrate may be used as a procedure for the development of a new onychomycosis diagnosis test in order to develop personalized and strain-specific treatment.

Acne Vulgaris, Atopic Dermatitis and Rosacea: The Role of the Skin Microbiota-A Review.

The skin harbors a huge number of different microorganisms such as bacteria, fungi and viruses, and it acts as a protective shield to prevent the invasion of pathogens and to maintain the health of the commensal microbiota. Several studies, in fact, have shown the importance of the skin microbiota for healthy skin. However, this balance can be altered by intrinsic and extrinsic factors, leading to the development of skin disease, such as acne vulgaris (AV), atopic dermatitis (AD) and rosacea(RS). Although these diseases are widespread and affect both adolescents and adults, the scientific correlation between these disorders and the skin microbiota and physiological parameters (TEWL, hydration and lipid composition) is still unclear. This review aims to investigate the current literature regarding the correlation between the skin microbiota and its imbalance underlying microbiological aspects, how the skin microbiota changes over the course of the disease and the current possible treatments. The following reported studies show a general imbalance of the bacterial flora. For this reason, more in-depth studies are necessary to explore the different subspecies and strains involved in all three diseases.

N-acetylcysteine (NAC) and Its Role in Clinical Practice Management of Cystic Fibrosis (CF): A Review.

N-acetylcysteine is the acetylated form of the amino acid L-cysteine and a precursor to glutathione (GSH). It has been known for a long time as a powerful antioxidant and as an antidote for paracetamol overdose. However, other activities related to this molecule have been discovered over the years, making it a promising drug for diseases such as cystic fibrosis (CF). Its antioxidant activity plays a key role in CF airway inflammation and redox imbalance. Furthermore, this molecule appears to play an important role in the prevention and eradication of biofilms resulting from CF airway infections, in particular that of Pseudomonas aeruginosa. The aim of this review is to provide an overview of CF and the role that NAC could play in preventing and eliminating biofilms, as a modulator of inflammation and as an antioxidant, restoring the redox balance within the airways in CF patients. To do this, NAC can act alone, but it can also be used as an adjuvant molecule to known drugs (antibiotics/anti-inflammatories) to increase their activity.

Evaluation of the Mucoadhesive Properties of Chitosan-Based Microstructured Lipid Carrier (CH-MLC).

Different mucoadhesive systems have been studied in recent years to increase the residence time of the delivery systems and to prolong the release of the drug. The aim of this work was to evaluate the mucoadhesive properties of chitosan-based Microstructured Lipid Carrier (CH-MLC) with a new approach which requires chitosan and mucin to be compacted into a tablet and mucoadhesion to be assessed on a non-mucoadhesive substrate. This type of test showed that chitosan maintains a close bond with mucin even in the presence of a fluid and even encapsulated in microparticles. After this, using a bioreactor, the release of N-acetylcysteine (NAC) from the microparticles (NA-CH-MLC) through a layer of mucus mimicking the pathological conditions of a patient with cystic fibrosis was tested. The release of the active from NAC-CH-MLC demonstrated how the chitosan inside the microparticles acts as a penetration enhancer and how the microparticles can impart a prolonged release over time.

Dosage variability of veterinary drug products, containing furosemide, linked to tablet splitting.

Background: Furosemide is a potent diuretic drug widely used to treat congestive heart failure in dogs and cats, but it shows remarkable variability in bioavailability and efficacy when administered orally. In particular, a different diuretic effect can be detected after repeated administrations of the same medicinal product in the same animal. For this reason, we investigate the possible reasons for this peculiar behavior. Drug products for veterinary andhuman use are compared in terms of variability for tablet splitting, in vitro dissolution profiles (in different fluids that could simulate the gastrointestinal environment of pets), and drug distribution uniformity. Aim: To study the in vitro performances of drug products in terms of variability. Methods: Five veterinary products and five products for human use, containing different furosemide doses, are characterized. Tablets splitting uniformity, in vitro dissolution profiles in different fluids that could simulate the gastrointestinal environment of the different species, and drug content distribution, were tested. Results: The in vitro dissolution profiles of the different medicines are comparable but confirm a different dissolution rate as a function of the medium pH and volume. Many of the products considered show wide variability in the division performances of the scored tablets, and this problem could lead to the detected fluctuations in the diuretic effect. The four-leaf clover shape of a veterinary product appears to give rise to more uniform fractions. A uniform distribution of the drug in the tablets and their fractions is confirmed for all the products considered. Conclusion: The possibility of tablets splitting allows considerable dosage flexibility, but a non-uniform break of the tablets to obtain the dosage suitable for the pet's weight, can cause dangerous over-or sub-dosing condition, especially in critical pathologies and in small breed pets.

Production and characterization of bovine hoof membranes as standardized in vitro model for nail studies.

Several studies can be found using bovine hoof membranes as a nail in vitro model. Most of them are actually permeability studies, while it is very hard to find reference in literature related to the use of those membranes to evaluate safety and efficacy of products. In facts, some effects, both desirable or not, are not strongly related to the penetration of the products thru all of the nail plate keratin layers. There are morphological characteristics and properties such as mechanical ones which could be affected even by a product acting on the surface of the nail. Moreover, hoof membranes production is not a standardized procedure, as well as membranes characterization which is a critical step to deal with when we are looking for a specific in vitro model. In this work, hoof membranes production is described in detail, along with the characterization techniques and parameters chosen for studying the model, such as contact angle measurement and mechanical properties assessment. The production method developed in this work has shown to be effective, making it possible to obtain membranes with desirable thickness, homogenous morphology and suitable mechanical properties. Mechanical properties were the most challenging to be assessed, also for the poor coverage of the topic by scientific literature. In particular the mechanical assessment has never been used before with this specific aim thus this research could be considered as a feasibility protocol in order to obtain a suitable nail model for further studies concerning drug permeability or safety and efficacy of final products .

Microstructured Lipid Carriers (MLC) Based on N-Acetylcysteine and Chitosan Preventing Pseudomonas aeruginosa Biofilm.

The aim of this work was the development of microstructured lipid carriers (MLC) based on chitosan (CH) and containing N-acetylcysteine (NAC), a mucolytic and antioxidant agent, to inhibit the formation of Pseudomonas aeruginosa biofilm. MLC were prepared using the high shear homogenization technique. The MLC were characterized for morphology, particle size, Z potential, encapsulation efficiency and drug release. The antioxidant properties of NAC-loaded microstructured carriers were evaluated through an in vitro spectrophotometer assay. Finally, the activity of NAC-CH-MLC on biofilm production by Pseudomonas aeruginosa was also evaluated. Results obtained from this study highlighted that the use of chitosan into the inner aqueous phase permitted to obtain microstructured particles with a narrow size range and with good encapsulation efficiency. NAC-loaded MLC showed higher antioxidant activity than the free molecule, demonstrating how encapsulation increases the antioxidant effect of the molecule. Furthermore, the reduction of biofilm growth resulted extremely high with MLC being 64.74% ± 6.2% and 83.74% ± 9.95%, respectively, at 0.5 mg/mL and 2 mg/mL. In conclusion, this work represents a favorable technological strategy against diseases in which bacterial biofilm is relevant, such as cystic fibrosis.

Efficacy and Acceptability of a New Water-Soluble Nail Strengthener Containing Pistacia lentiscus and Hyaluronic Acid to Improve the Appearance of Brittle Nails versus Untreated Nails: In vitro and Clinical Evidence.

INTRODUCTION: Brittle nail syndrome is characterized by dry, weak, easily breakable nails that show inelasticity, splitting and overall nail plate fragility. OBJECTIVE: This paper describes in vitro and clinical studies using bovine hooves designed to assess the efficacy, compatibility and acceptability of a water-soluble nail strengthener (WSNS), containing Pistacia lentiscus and hyaluronic acid, for the treatment of patients affected by brittle nails. METHODS: In the in vitro study, the WSNS was tested versus placebo and a marketed product on bovine hoof membranes, applied once daily for 14 days for evaluation of firmness, viscoelasticity and thickness before and after applications. In a clinical study, 23 female subjects affected by brittle nails were included, and the WSNS was applied once daily for 3 months. Signs and symptoms were rated by the investigators and by the participants during treatment at 28 and 84 days with different methods and dermoscopic images. Subjective efficacy was evaluated by specific questionnaires. RESULTS: In the in vitro study, the daily application of the WSNS and marketed product led to a significant increase in firmness index. In the clinical study, the nails on the treated hand presented an improvement in nail appearance and weakness, after 28 and 84 days of WSNS application, respectively. The nails not treated showed no improvement. The WSNS was well tolerated. CONCLUSIONS: The WSNS containing Pistacia lentiscus and hyaluronic acid was shown to significantly increase nail firmness in the in vitro study. In the clinical study, WSNS significantly improved brittle nail appearance. The hydrosolubility and easy-to-apply format of WSNS were reported to be factors of a good compliance. We consider this product as an important tool to improve and reinforce the aspect of brittle nails.

In vivo evaluation of the effectiveness of biocellulose facial masks as active delivery systems to skin.

BACKGROUND: In recent years, bacterial cellulose (BC), or biocellulose, a natural polymer synthesized by certain bacteria, has attracted great interest in dermatology and cosmetic applications. Several bioactive ingredients are currently loaded into BC masks. However, only a few studies have reported the effectiveness of such delivery systems. AIM: The aim of this study was to evaluate the effect on skin parameters of three biocellulose masks formulated to have different cosmetic effects (anti-aging, lifting, and cell renewal). In particular, skin moisturizing, skin color, skin viscoelastic properties, skin surface smoothness, wrinkle reduction, dermal homogeneity, and stratum corneum renewal were evaluated. MATERIALS AND METHODS: The study involved 69 healthy Caucasian female volunteers between 25 and 64 years, who were divided into three different studies. Biocellulose facial masks were applied using the split-face method three times a week for 4-8 weeks depending on the study. RESULTS: The results obtained from this work highlight that biocellulose masks are very well tolerated. A significant decrease in skin roughness and wrinkle breadth, and an improvement in dermal homogeneity and firmness, was observed after 2 months of treatment with "anti-aging" masks. A significant improvement in skin firmness and elasticity was observed after 1 month of treatment with "lifting" masks. Furthermore, a 1-month treatment with "cell renewal" masks promoted the production of new skin cells through a mild exfoliating action. CONCLUSIONS: This study highlights that biocellulose masks are effective delivery systems to successfully release into the skin several types of active compounds exerting many beneficial effects.

Nail StrainStress Meter NM 100: A novel in vivo method to characterize biomechanical properties of nails.

BACKGROUND: Nowadays, nail care products are extremely important both in medical and cosmetic fields. Actually, there are only a very few "in vivo" methods to evaluate the safety and the efficacy of nail products. METHODS: The new apparatus, based on a recently patented technology, is developed for the "in vivo" evaluation of nails in terms of thickness, structural firmness, flattening, and bending properties. The device analyzes nails by an "in vivo" non-invasive methodology in a timely way and with high accuracy. The assessment of the resistance to compression measures the cohesion of the nail matrix (nail firmness), while the evaluation of the resistance to transversal deformation detects the elasticity of the nail plate. Furthermore, the apparatus is able to assess the nail thickness and the flexibility of their distal edge. RESULTS: The instrument provides nail thickness and several parameters reflecting mechanical properties of nail plate: Viscoelasticity expressed as viscoelasticity index (VI), structural strength/ firmness expressed as Firmness Index (FI), and viscoelasticity of the distal edge expressed as Bending Index (BI). CONCLUSIONS: The instruments described in this work represent an innovative apparatus for the safety and efficacy evaluation of nail products in several fields: cosmetics, pharmaceuticals, and medical devices.

Evaluation of Mechanical Properties and Volatile Organic Extractable to Investigate LLDPE and LDPE Polymers on Final Packaging for Semisolid Formulation.

Plastic material is used for a wide variety of commercial packaging due to being inexpensive, lightweight, and due to its resistance. In pharmaceutics, container-content compatibility studies are required for product authorization. Many guidelines and publications are available; however, the information is often only related to the raw materials used to produce packaging. During the manufacturing process, substances can be added to improve the product characteristics and performance, resulting in a processed material that is considerably different from the unprocessed material. In this study, the mechanical properties of low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) specimens fabricated according to standard ISO 527 and specimens fabricated with the same materials, but obtained from final packaging, were evaluated. Furthermore, we examined the interaction between a semisolid formulation and LLDPE and LDPE as a final packaging, by subjecting two samples to accelerated degradation testing. Then, mechanical properties and volatile organic extractable were evaluated. Simulated solar radiation did not induce changes in the packaging mechanical properties and no extracts were detectable. The thermal shock strongly influenced the mechanical behavior, and interactions between packaging contents were identified. The present work underlines the difference between analyzing the standard ISO specimens versus samples obtained from final packaging in order to evaluate the packaging under real use conditions. An evaluation on the final packaging, instead on standard specimens, can provide information about the plastic material after the manufacturing process and the interaction between packaging and content.

Comparative behavior between sunscreens based on free or encapsulated UV filters in term of skin penetration, retention and photo-stability.

BACKGROUND: The growing incidence of photodamaging effects caused by UV radiation (e.g. sunburn, skin cancer) has increased the attention from health authorities which recommend the topical application of sunscreens to prevent these skin damages. The economic stakes for those companies involved in this international market are to develop new UV filters and innovative technologies to provide the most efficient, flexible and robust sunscreen products. Today the development of innovative and competitive sunscreen products is a complex formulation challenge. Indeed, the current sunscreens must protect against skin damages, while also being safe for the skin and being sensory and visually pleasant for the customers when applied on the skin. Organic UV filters, while proposing great advantages, also present the risk to penetrate the stratum corneum and diffuse into underlying structures with unknown consequences; moreover, their photo-stability are noted thorny outcomes in sunscreen development and subsequent performance. In recent years, the evaluation of the interaction between skin and sunscreen in terms of penetration after topical application has been considered from European authority but still its testing as their photo-stability assessment are not mandatory in most countries. OBJECTIVE: This study, based on in-vitro approaches, was performed to evaluate and compare the retention and the penetration of organic UV filters in free or encapsulated form inside the skin as well as their respective photo-stability. METHODS: Sunscreen formulation with a combination of Avobenzone and Octocrylene in "free form" and a formulation using the same UV filters but encapsulated in a sol-gel silica capsule, were analyzed and compared by FTIR Imaging Spectroscopy. Tape stripping method was used to investigate the penetration of these UV filters inside the stratum corneum. Their photo-stabilities were evaluated by spectroscopic measurements (FTIR, UV/Vis) and standard measurements were calculated: AUC (Area Under the Curve) and SPF (Sun Protection Factor). RESULT: With traditional formulation, the organic UV filters penetrated significantly into the stratum corneum while the same UV filters combined with encapsulation technology remained on the skin surface. The encapsulation technology also improved significantly their stability. CONCLUSION: Encapsulation technology is a promising strategy to improve the efficacy of sunscreen product using organic UV filters and to reduce safety problem. On the other hand, this study highlighted the pertinence of the FTIR Spectroscopy to test, compare and investigate sunscreen formulations.

Stability Study of Sunscreens with Free and Encapsulated UV Filters Contained in Plastic Packaging.

Sunscreens play a fundamental role in skin cancer prevention and in protection against photo-aging. UV filters are often photo-unstable, especially in relation to their vehicles and, being lipophilic substances, they are able to interact with plastic packaging. Finally, UV filter stability can be significantly affected by the routine use of the product at high temperatures. This work aims to study the stability of sunscreen formulations in polyethylene packaging. Butyl methoxydibenzoylmethane and octocrylene, both in a free form and as encapsulated filters were chosen as UV filters. Stability evaluations were performed both in the packaging and on the formulations. Moreover, a further two non-destructive techniques, near-infrared (NIR) spectroscopy and a multiple light scattering technique, were also used to evaluate the stability of the formulation. Results demonstrated clearly that all of the pack underwent significant changes in its elastic/plastic behavior and in external color after solar irradiation. From the evaluation of the extractable profile of untreated and treated packaging material an absorption of 2-phenoxyethanol and octocrylene were shown. In conclusion, the results highlighted clearly that a reduction of the UV filter in the formulation packed in high-density polyethylene/low-density polyethylene (HDPE/LDPE) material can occur over time, reducing the protective effect of the product when applied to the skin.

Development and characterization of new and scalable topical formulations containing N-acetyl-d-glucosamine-loaded solid lipid nanoparticles.

N-Acetyl-d-glucosamine (NAG) has been recently considered for topical treatment of hyperpigmentation disorders due to its inhibitory effect on thyrosinase enzymes in melanocytes. NAG is a precursor of hyaluronic acid, increasing its amount in skin, and consequently, preserving the skin hydration and elasticity. It may also act as an emulsion stabilizer. Solid lipid nanoparticles (SLN) are advanced delivery systems successfully used in pharmaceutical and cosmetic formulations for the improvement of active molecules penetration into the skin. Therefore, this work aimed to develop and characterize stable and scalable topical formulations containing NAG-loaded SLN. NAG was incorporated in SLN which were prepared by two high shear homogenizers and characterized regarding its morphology and particle size by transmission electron microscopy and photon correlation spectroscopy, respectively. Oil emulgel and hydrogel were used as carriers of NAG-loaded SLN. Several parameters were evaluated, including the droplet size distribution, rheology, pH and topical delivery by different techniques. It was observed that SLN size was significantly dependent on NAG incorporation and homogenization process. Most tested SLN parameters appeared to be quite suitable, that is, spherical and well-defined SLN with approximately 258 nm and -30 mV. Hereafter, both gels containing SLN presented a pseudoplastic flow. Emulgel formulation containing NAG-loaded SLN allowed a higher NAG permeation through the SC compared to the respective control (about 0.8 µgcm-2 h-1). According to the results obtained, it can be suggested that NAG acts as an emulsion stabilizer. This stabilization was also particularly dependent on the homogenizer type which is quite important for scale-up process. This study demonstrated the potential of scalable SLN formulations to improve NAG topical delivery contributing to the improvement of skin properties on several skin disorders.

Scar Remodeling with the Association of Monopolar Capacitive Radiofrequency, Electric Stimulation, and Negative Pressure.

OBJECTIVE: A study was established to objectively assess the effects of low-intensity electromagnetic and electric stimulation plus negative pressure on mature scars. BACKGROUND: Radiofrequency plus negative pressure therapy demonstrated a favorable reorganization and regeneration of the collagen and elastic fibers and was proposed for the treatment of cellulitis and skin stretch marks. METHODS: Twenty-six mature scars in 20 Caucasian patients (15 females and 5 males) were enrolled in the study. The treatments were carried out with a Class I, BF-type electromedical device equipped with a radiofrequency generator, an electric pulse generator, and a vacuum pump twice a week for 3 months. Corneometry, transepidermal water loss, elastometry, colorimetry, and three-dimensional skin surface pattern were objectively assessed with Multi Probe Adapter System MPA and PRIMOS pico. A subjective assessment was carried out with the VAS and PSAS scales. Each scar was compared before and after the treatment and with the skin in the corresponding healthy contralateral anatomical area at the same times. RESULTS: Reduction of the scar surface wrinkling and overall scar flattening were demonstrated after the treatment. The scar slightly tended to approach the color and elasticity of healthy skin too. CONCLUSIONS: The combined local treatment of mature scars with low-intensity electromagnetic and electric stimulation in association with negative pressure might suggest a favorable synergic effect on the scar collagen and elastic fiber remodeling.

Determination of N-acetylglucosamine in cosmetic formulations and skin test samples by hydrophilic interaction liquid chromatography and UV detection.

N-Acetylglucosamine is an ingredient in pharmaceuticals, nutritional supplements and in cosmetics. N-Acetylglucosamine in cosmetics is expected to improve skin hydration, reparation, and to contribute as anti-wrinkle agent. This study reports on the validation and application of an HPLC method based on HILIC and UV detection for determining N-acetylglucosamine in cosmetics and in samples obtained after testing the skin exposed to cosmetics formulations. The chromatographic column used is a ZIC(®)-pHILIC (150 mm × 4.6 mm, 5 µm particle size) on which a mobile phase containing acetonitrile-aqueous KH2PO4 (70:30, v/v) 15 mM was applied in isocratic elution mode injecting 20 µl of sample at 0.5 ml/min constant flow-rate and 10±1°C column temperature. Under these conditions the total run time was 10 min and N-acetylglucosamine eluted baseline separated from all other compounds in the samples. Calibration in the range from 40 to 80 µg/ml allowed to assess the method linearity (R(2)>0.999) in a concentration range corresponding to about 50% to 120% of the expected levels of N-acetylglucosamine in the formulations. Precision expressed by RSD% was always better than 2% in intra-day and inter-day assays of authentic samples. Accuracy was in all cases within 95-105% of the expected concentration value in formulations containing N-acetylglucosamine. The sensitivity of the method was at the level of 10 µg/ml as limit of detection, and at 40 µg/ml as limit of quantitation. The application of the method to formulations containing solid lipid nanoparticles documents its usefulness in cosmetic quality control. The results witness that the method is also suitable for the determination of N-acetylglucosamine in samples obtained from skin test strips.