Historical perspective on the use of visual grading scales in evaluating skin irritation and sensitization

Image based quantification method reveals differential patterns of lip desquamation associated with age and sex

The rough surface of lip skin is a dermatological and aesthetic issue that affects facial appearance. While several studies have addressed this common problem, none of them have exclusively utilized image analysis techniques. In this study, we aimed to quantify lip desquamation from facial images in a total of 55 participants and compare the results to those obtained from the tape-stripping method. The central region of the lower lip was extracted from each facial image, and global thresholding was applied using the threshold value T, which is defined as Mean + 2.5 SD. In this equation, Mean and SD represent the average and standard deviation of each grayscale values within the image, respectively. The desquamation rate was calculated as the proportion of pixels corresponding to desquamated flakes within the analyzed region. We found that our approach accurately represented the lip surface states, with a strong correlation with visual assessment (VA) scores (r = 0.715, p < 0.001). To investigate the relationship between lip desquamation and age, we further analyzed the facial images of 1,000 individuals. A gradual decline in lip desquamation with age was observed in males (r = -0.151, p < 0.001) and females over 38 years (r = -0.133, p < 0.05). In contrast, the variation of lip desquamation among females under the age of 38 showed an increasing trend (r = 0.234, p < 0.01). It is notable that the most pronounced differences between sexes were only observed in individuals in their 20s (p < 0.001). Such results imply that the characteristics of epithelial layer of lip can be segmented based on chronological age and sex. These notable changes in lip desquamation were discovered for the first time in this study. Given the current ease of acquiring image data, our image-based method has the potential to advance the lip skin research.

Microneedles containing Cucumaria frondosa polysaccharides and 3-acetylaconitine exert analgesic, anti-inflammatory and chondroprotective activity for knee osteoarthritis

3-Acetylaconitine (AAC) is a commercially analgesic drug for arthritis, however, due to its narrow safety range, its clinical application is limited. The objective of the study was to investigate the combined effect of Cucumaria frondosa polysaccharide (CFP) and AAC in microneedles on knee osteoarthritis (KOA). The characterization of microneedles was conducted and a rat model of monosodium iodoacetate (MIA)-induced KOA was established to evaluate the anti-inflammatory and analgesic activity in this study. The inhibitory effects on cartilage degradation and synovial inflammation were determined by morphological observation of the knee joint, pathological and imaging results. The von Frey pain threshold and hind limb weight bearing test were used to evaluate the effect of microneedles on pain relief. The results showed that microneedles had the mechanical strength to penetrate the skin and dissolved well in the skin for drug delivery within 30 min after patch administration. Furthermore, AAC-MN and CFP-AAC-MN both played roles in relieving pain, reducing cartilage degeneration and inhibiting synovial inflammation in KOA. In summary, CFP combined with AAC loading into microneedles exhibited higher skin penetration and more advantages in inhibiting cartilage damage and inflammation compared to AAC alone.

In Situ Forming, Enzyme-Responsive Peptoid-Peptide Hydrogels: An Advanced Long-Acting Injectable Drug Delivery System

Long-acting drug delivery systems are promising platforms to improve patient adherence to medication by delivering drugs over sustained periods and removing the need for patients to comply with oral regimens. This research paper provides a proof-of-concept for the development of a new optimized in situ forming injectable depot based on a tetrabenzylamine-tetraglycine-d-lysine-O-phospho-d-tyrosine peptoid-D-peptide formulation ((NPhe)4GGGGk(AZT)y(p)-OH). The chemical versatility of the peptoid-peptide motif allows low-molecular-weight drugs to be precisely and covalently conjugated. After subcutaneous injection, a hydrogel depot forms from the solubilized peptoid-peptide-drug formulation in response to phosphatase enzymes present within the skin space. This system is able to deliver clinically relevant concentrations of a model drug, the antiretroviral zidovudine (AZT), for 35 days in Sprague-Dawley rats. Oscillatory rheology demonstrated that hydrogel formation began within ∼30 s, an important characteristic of in situ systems for reducing initial drug bursts. Gel formation continued for up to ∼90 min. Small-angle neutron scattering data reveal narrow-radius fibers (∼0.78-1.8 nm) that closely fit formation via a flexible cylinder elliptical model. The inclusion of non-native peptoid monomers and D-variant amino acids confers protease resistance, enabling enhanced biostability to be demonstrated in vitro. Drug release proceeds via hydrolysis of an ester linkage under physiological conditions, releasing the drug in an unmodified form and further reducing the initial drug burst. Subcutaneous administration of (NPhe)4GGGGk(AZT)y(p)-OH to Sprague-Dawley rats resulted in zidovudine blood plasma concentrations within the 90% maximal inhibitory concentration (IC90) range (30-130 ng mL-1) for 35 days.

In Vivo Evaluation of Miconazole-Nitrate-Loaded Transethosomal Gel Using a Rat Model Infected with Candida albicans

Miconazole nitrate (MCNR), an antifungal drug, is used to treat superficial infections. The objective of the current study was to assess the antifungal effectiveness of MCNR-loaded transethosomal gel (MNTG) against Candida albicans in an in vivo rat model. The outcomes were compared with those of the miconazole nitrate gel (MNG) and marketed Daktarin® cream (2%) based on histopathological and hematological studies. The results of the skin irritation test revealed the safety profile of the MNTG. The MNTG demonstrated the greatest antifungal activity in the histological analysis and the visible restoration of the skin, and the rats revealed an apparent evidence of recovery. Compared to the untreated group, the treated group's lymphocyte and white blood cells counts increased, but their eosinophil counts decreased. In conclusion, MNTG exhibited the greatest antifungal activity, which might be connected to the improved skin permeability of the transethosome's nanosized vesicles. Therefore, it could be considered a promising carrier for topical usage and the treatment of cutaneous candidiasis. More clinical research needs to be performed in order to demonstrate its effectiveness and safe usage in humans.

Examination of the Rate and Extent of Drug Released from Commercial Topical Delivery Systems During Wear: An Example with Lidocaine Topical Systems

OBJECTIVE

This study aimed to determine the extent and rate of lidocaine released in vivo from two bioequivalent topical delivery systems (TDS) by using complementary assessments: pharmacokinetic analysis in healthy human volunteers, and residual lidocaine in TDS following 12 h of wear. The goal was to explore a potentially more clinically meaningful strength presentation than percent active pharmaceutical ingredient loaded in topical systems.

METHODS

A three-arm, open-label, crossover clinical study was conducted in 23 human subjects, with 5% lidocaine topical systems from two manufacturers, and intravenous lidocaine administration. Residual drug and LC-MS/MS analyses were performed on worn TDS and serum samples. The rate and extent of drug released from the TDS during wear were determined through (1) calculations of consumed lidocaine via analysis of residual drug in worn TDS, and (2) a pharmacokinetic approach via derivation of the absolute clearance and serum lidocaine concentration at steady state.

RESULTS

Overall the pharmacokinetic approach underestimated the amount transferred to the subject and exhibited greater variability, which may relate to natural inter-subject variability in pharmacokinetic parameters. Further, lidocaine TDS are intended for localized, not systemic, delivery and this may also explain some of the variability seen in the systemic serum concentrations.

CONCLUSIONS

The residual drug and pharmacokinetic approaches align well for transdermal formulations, but the differences in administration route (topical versus transdermal) all but eliminates the potential use of the pharmacokinetic approach unless additional compartmental modeling is explored.

Pharmacokinetic Study of Islatravir and Etonogestrel Implants in Macaques

The prevention of HIV and unintended pregnancies is a public health priority. Multi-purpose prevention technologies capable of long-acting HIV and pregnancy prevention are desirable for women. Here, we utilized a preclinical macaque model to evaluate the pharmacokinetics of biodegradable ε-polycaprolactone implants delivering the antiretroviral islatravir (ISL) and the contraceptive etonogestrel (ENG). Three implants were tested: ISL-62 mg, ISL-98 mg, and ENG-33 mg. Animals received one or two ISL-eluting implants, with doses of 42, 66, or 108 µg of ISL/day with or without an additional ENG-33 mg implant (31 µg/day). Drug release increased linearly with dose with median [range] plasma ISL levels of 1.3 [1.0-2.5], 1.9 [1.2-6.3] and 2.8 [2.3-11.6], respectively. The ISL-62 and 98 mg implants demonstrated stable drug release over three months with ISL-triphosphate (ISL-TP) concentr54ations in PBMCs above levels predicted to be efficacious for PrEP. Similarly, ENG implants demonstrated sustained drug release with median [range] plasma ENG levels of 495 [229-1110] pg/mL, which suppressed progesterone within two weeks and showed no evidence of altering ISL pharmacokinetics. Two of the six ISL-98 mg implants broke during the study and induced implant-site reactions, whereas no reactions were observed with intact implants. We show that ISL and ENG biodegradable implants are safe and yield sufficient drug levels to achieve prevention targets. The evaluation of optimized implants with increased mechanical robustness is underway for improved durability and vaginal efficacy in a SHIV challenge model.

Optimized multiherbal combination and in vivo anti-skin aging potential: a randomized double blind placebo controlled study

The present study aimed to optimize a multi-herbal combination exerting the greatest antioxidant property using statistical method for anti-skin aging application as well as to elucidate its in vivo safety and anti-skin aging potential. The multi-herbal combination was optimized using a two-level, full factorial approach by exploring the correlation between the concentrations (0-3%w/v) of three extracts from Centella asiatica (CA), Momordica cochinchinensis (MA), Phyllanthus emblica (EM). An anti-skin aging emulsion containing the optimized combination was then developed and evaluated for its physicochemical characteristics with its stability under storage conditions. The in vivo anti-skin aging potential of the emulsion was subsequently investigated among 60 women in a randomized, double-blind, placebo-controlled study. Skin hydration, elasticity and wrinkles at eye and cheek areas were measured at baseline, after 30 and 60 days of application. Before performance testing, in vivo skin irritation was evaluated using the patch test and homogeneity between groups was also statistically analyzed. According to the model describing the significant main effects of each extract and interaction effects between extracts on percent inhibition against DPPH radicals, the best multi-herbal combination consisted of 3%w/v EM and 3%w/v CA. The developed emulsion containing the combination presented smooth soft texture with good stability in terms of physical characteristics and biological property. Regarding the clinical study, no skin erythema and edema was reported among in all volunteers. After 60 days of application, significantly improved skin hydration, elasticity and wrinkles were observed in the test group. In addition, significantly reduced wrinkles were observed after 60 days in both skin areas of the test group. The anti-skin aging emulsion containing this optimized combination exhibited good safety and performance. Ultimately, this product comprises an effective anti-skin aging formulation for applications.

Ultra-long-acting in-situ forming implants with cabotegravir protect female macaques against rectal SHIV infection

Ultra-long-acting delivery platforms for HIV pre-exposure prophylaxis (PrEP) may increase adherence and maximize public health benefit. We report on an injectable, biodegradable, and removable in-situ forming implant (ISFI) that is administered subcutaneously and can release the integrase inhibitor cabotegravir (CAB) above protective benchmarks for more than 6 months. CAB ISFIs are well-tolerated in female mice and female macaques showing no signs of toxicity or chronic inflammation. In macaques, median plasma CAB concentrations exceed established PrEP protection benchmarks within 3 weeks and confer complete protection against repeated rectal SHIV challenges. Implant removal via a small incision in 2 macaques at week 12 results in a 7- to 48-fold decrease in plasma CAB levels within 72 hours. Modeling to translate CAB ISFI dosing suggests that a 3 mL injection would exceed protective benchmarks in humans for over 5 months post administration. Our results support the clinical advancement of CAB ISFIs for ultra-long-acting PrEP in humans.

Safety and efficacy of a biodegradable implant releasing tenofovir alafenamide for vaginal protection in a macaque model

OBJECTIVES

To advance the initiative of ending the global epidemic, long-lasting HIV protection is needed through sustained release of antiretroviral drugs for months to years. We investigated in macaques the safety and efficacy of biodegradable polycaprolactone implants releasing tenofovir alafenamide for HIV pre-exposure prophylaxis (PrEP).

METHODS

Implants were administered subcutaneously in the arm using a contraceptive trocar. Efficacy against vaginal simian-HIV (SHIV) infection was investigated in six pigtailed macaques that received two tenofovir alafenamide implants (0.35 mg/day), one in each arm, for a total release rate of tenofovir alafenamide at 0.7 mg/day. Macaques were exposed to SHIV twice weekly for 6 weeks. Statistical analyses were used to compare outcome with eight untreated controls. Histological assessments were performed on skin biopsies collected near implantation sites.

RESULTS

Median (range) tenofovir diphosphate level in PBMCs was 1519 (1068-1898) fmol/106 cells. All macaques with tenofovir alafenamide implants were protected against vaginal SHIV infection. In contrast, 7/8 controls were infected after a median of 4 SHIV exposures (P = 0.0047). Histological assessment of tissues near tenofovir alafenamide implant sites showed inflammation and necrosis in 5/6 animals, which were not evident by visual inspection.

CONCLUSIONS

We demonstrated complete protection against vaginal SHIV infection with two implants releasing a total of 0.7 mg of tenofovir alafenamide per day. We also identified tenofovir diphosphate concentrations in PBMCs associated with complete vaginal protection. Consistent with previous findings, we observed adverse local toxicity and necrosis near the tenofovir alafenamide implant site. Improved tenofovir alafenamide implants that are safe and maintain high efficacy have the potential to provide long-lasting protection against vaginal HIV infection.

Delta-5® oil, containing the anti-inflammatory fatty acid sciadonic acid, improves skin barrier function in a skin irritation model in healthy female subjects

Background

Sciadonic acid (SA) is an anti-inflammatory fatty acid displacing arachidonic acid (ARA) from specific phospholipid pools, thus modulating downstream pro-inflammatory lipid mediators. Its novel anti-inflammatory actions have been studied in vitro, in pre-clinical models, and stemming from testimonials, after topical- and oral application. It has not been tested in a formal clinical study for topical benefits previously. Skin barrier layer was our focus as it has a critically important role in maintaining skin moisture balance.

Methods

Herein, forearm skin was left undamaged; or barrier layer was chemically-damaged with 2% sodium lauryl sulfate (SLS) for 24 h. SLS-damaged skin was left untreated or treated with Delta-5® oil containing 24% SA twice daily for 27 days. Barrier function was assessed by open chamber transepidermal water loss (TEWL) and skin surface impedance on days 0 (clear skin), -1 (1-day post-SLS), -2 (2-days post-SLS, 1-day post-Delta-5), -3, -7, and − 28.

Results

Relative to day 1, Delta-5 oil statistically significantly decreased TEWL vs. untreated damaged sites, on days 3 (125% more reduced), -7 (74% more reduced), and − 28 (69% more reduced). Decreases in TEWL following chemical damage indicates improved skin barrier repair and healing. Similar patterns were quantified for skin impedance. There was also reduced redness observed on days 3 and − 7 with Delta-5 oil vs. untreated SLS-damaged skin.

Conclusions

Delta-5 oil thus has anti-inflammatory potential in human skin, under controlled clinical conditions, to accelerate irritant-induced healing, and improve skin barrier function. Improvement in barrier function would benefit dermatitis, acne, eczema, and skin scarring. In normal skin, Delta-5 oil has potential to promote healthy, moisturized skin; and improve skin structure, elasticity, and firmness.

Skin Reaction Report Form: Development and Design of a Standardized Report Form for Skin Reactions Due to Medical Devices for Diabetes Management

BACKGROUND

Skin reactions due to medical devices for diabetes management have become a common problem in diabetes technology. There is a varying degree in how detailed skin reactions are described in scientific literature and diabetes practice, and no uniform structured documentation is given. Whereas most articles only describe findings, some others already document final diagnoses, such as contact dermatitis. Furthermore, inconsistent wordings for comparable issues were used.

METHODS

A more detailed and standardized documentation, possibly facilitated by a generally accepted guideline for structured descriptions, of skin reactions could be helpful to enable better differentiations between the described skin reactions. Therefore, a report form to assess skin reactions due to medical devices in diabetes therapy was developed and will be presented in this article.

RESULTS

The one-page report form is divided into four categories and a separate instruction paper. Beside general information the form includes the location, size, severity and duration of skin appearances, the grading of itching, and suspected diagnoses.

CONCLUSION

A consistent use of the form in daily practice and clinical trials could facilitate a fast and standardized documentation and help to evaluate the occurrence and severity of different skin reactions due to medical devices in diabetes management.

Inter-rater variability in patch test readings and final interpretation using store-forward teledermatology

BACKGROUND

Data regarding teledermatology for patch testing are limited.

OBJECTIVES

Compare patch test readings and final interpretation by two in-person dermatologists (IPDs) with eight teledermatologists (TDs).

METHODS

Patch tested patients had photographs taken of 70 screening series of allergens at 48 hours and second readings. Eight TDs reviewed photos and graded reactions (negative, irritant, doubtful, +, ++, +++) at 48 hours and second readings; in addition, they coded a final interpretation (allergic, indeterminant, irritant, negative) for each reaction. TDs rated overall image quality and confidence level for each patient and patch test reaction, respectively. Percentage of TD-IPD agreement based on clinical significance (success, indeterminate, and failure) was calculated. Primary outcome was agreement at the second reading.

RESULTS

Data were available for 99, 101, and 66 participants at 48 hours, second reading, and final interpretation, respectively. Pooled failure (+/++/+++ vs negative) at second reading was 13.6% (range 7.9%-20.4%). Pooled failure at 48 hours and final interpretation was 5.4% (range 2.9%-6.8%) and 24.6% (range 10.2%-36.8%), respectively. Confidence in readings was statistically correlated with quality of images and disagreement.

CONCLUSION

For patch testing, teledermatology has significant limitations including clinically significant pooled failure percentages of 13.6% for second readings and 24.6% for final interpretation.

The 21-day cumulative irritation assay in man: a half-century summary and re-evaluation

The 21-day cumulative irritation test (21-day CIT) has been widely used in dermatopharmacology and dermatotoxicology to assess the irritation potential of topical products. Since described by Lanman in 1968, it has been modified, shortened, re-evaluated, and statistically analysed by multiple groups of authors. As the assay has been recommended in FDA draft guidance, we bring subsequent experience to date. The shorter 14-day version is commonly used and may be as adequate as the 21-day application when used to discriminate between moderate to strong irritants. While previous authors stopped the test when subjects experienced an irritation score of 3 or more, the FDA suggested moving the test to another anatomical site to complete in 21 days. This approach avoids assumptions, thus may be more accurate to quantify skin irritation. As the scoring is based on visual grading, the 21-day CIT also does not account for sensory irritation. Therefore, future studies need to propose a way to evaluate the sensation objectively in dermatological product development.

Determination of Rate and Extent of Scopolamine Release from Transderm Scōp® Transdermal Drug Delivery Systems in Healthy Human Adults

To estimate strength of a scopolamine transdermal delivery system (TDS) in vivo, using residual drug vs. pharmacokinetic analyses with the goal of scientifically supporting a single and robust method for use across the dosage form and ultimately facilitate the development of more consistent and clinically meaningful labeling. A two-arm, open-label, crossover pharmacokinetic study was completed in 26 volunteers. Serum samples were collected and residual scopolamine was extracted from worn TDS. Delivery extent and rate were estimated by (1) numeric deconvolution and (2) steady-state serum concentration determined from graphical and non-compartmental analyses. In residual drug analyses, mean ± SD scopolamine release rate was 0.015 ± 0.002 mg/h (11% RSD), vs. 0.016 ± 0.006 mg/h (35% RSD) from numeric deconvolution, 0.015 ± 0.005 mg/h (34% RSD) from graphical analysis, and 0.015 ± 0.007 mg/h (44% RSD) from non-compartmental analysis. In residual drug analyses, total drug released was 1.09 ± 0.11 mg (10% RSD), vs. 1.12 ± 0.40 mg (35% RSD) from numeric deconvolution, 1.07 ± 0.35 mg (33% RSD) from graphical analysis, and 1.07 ± 0.45 (42% RSD) from non-compartmental analysis. Extent and rate of scopolamine release were comparable by both approaches, but pharmacokinetic analysis demonstrated greater inter-subject variability.

A review of shampoo surfactant technology: consumer benefits, raw materials and recent developments

Surfactants form the core of all shampoo formulations, and contribute to a wide range of different benefits, including cleansing, foaming, rheology control, skin mildness and the deposition of benefit agents to the hair and scalp. The purpose of this review was to assist the design of effective, modern, shampoo surfactant technologies. The mechanisms through which surfactants help deliver their effects are presented, along with the appraisal techniques through which surfactant options can be tested and screened for product development. The steps that should be taken to select the most appropriate blend of surfactants are described, and useful information on the most widely used surfactants is provided. The review concludes with an examination of recent developments in 'greener' surfactants, 'sulphate-free' technologies and structured liquid phases for novel sensory properties and for suspending benefit agents.

Ocular pharmacokinetics and tolerability of bimatoprost ophthalmic solutions administered once or twice daily in rabbits, and clinical dosing implications

Purpose

Fixed-combination medications can benefit patients requiring multiple agents to lower their intraocular pressure (IOP), but combining agents with complementary mechanisms of action is challenging if their dosing frequency differs. This study compares in vivo pharmacokinetic and ocular tolerability of bimatoprost 0.01% ophthalmic solutions dosed once or twice daily. Reports of twice-daily dosing in glaucoma patients are also reviewed.

Methods

New Zealand White rabbits were administered bimatoprost 0.01% monotherapy or fixed-combination bimatoprost 0.01%/brimonidine 0.1%, once or twice daily in both eyes for 4 days. Ocular tissues were harvested and analyzed by liquid chromatography-tandem mass spectrometry. The pharmacokinetic parameters calculated included maximum observed concentration, time to maximum concentration, and area under the concentration-time curve.

Results

Due to extensive metabolism, bimatoprost concentration was below the quantitation limit by 1 hour post-dose in all samples. Bimatoprost acid exposure, however, could be measured up to 6–8 hours post-dose and was similar in the aqueous humor and iris-ciliary body (pharmacological site of action) of animals treated once or twice daily with either bimatoprost 0.01% or fixed-combination bimatoprost 0.01%/brimonidine 0.1%. Increasing dosage frequency in rabbits did not raise the incidence of drug-related conjunctival hyperemia (most common adverse event associated with bimatoprost use in humans), suggesting comparable ocular tolerability of the once- and twice-daily regimens for each formulation.

Conclusion

Bimatoprost 0.01% administered once or twice daily as monotherapy and in fixed-combination with brimonidine 0.1% in rabbits show similar pharmacokinetic profiles of bimatoprost acid, especially in the iris-ciliary body. Key findings from previous clinical studies suggest that by varying the concentration of benzalkonium chloride (a preservative with corneal penetration-enhancing properties), formulations of bimatoprost 0.01% can be administered once or twice daily. These findings support development of bimatoprost 0.01%-based fixed-dose combination therapies administered twice daily for patients who require multiple adjunctive medications to control their IOP.

Evaluation of a new topical skin protectant (RD1433) for the prevention and treatment of incontinence-associated dermatitis

Context Incontinence-associated dermatitis (IAD) is a type of moisture-associated dermatitis caused by repeated skin exposure to urine or stool. A product that could mitigate such symptoms would have a significant impact on cost of care and patients' quality of life. Objective This study compared the clinical efficacy of RD1433 and a comparator product (Vaseline®) in preventing and treating experimental IAD skin lesions. Materials and methods For the "prevention" part of the study, skin sites in eight human volunteers were treated daily for 5 d with either RD1433 or Vaseline® immediately prior to synthetic urine exposure. In the "treatment" part, exposure to synthetic urine was substituted for Vaseline® or RD1433 application on the first 2 d to promote the development of skin lesions prior to the application of the products from day three. Product efficacy was quantified by visual scoring and an array of biophysical instruments. Results Both RD1433 and Vaseline® significantly reduced lesion progression when applied as a prophylactic. When applied as a treatment (following establishment of skin lesions), RD1433 demonstrated a statistically significant improvement in several measures of skin function whereas there was no statistically significant improvement following treatment with Vaseline®. Conclusions The findings of this study suggest that RD1433 may be superior to Vaseline® in the prevention and treatment of experimental IAD lesions. Clearly, further work is required to establish the efficacy of RD1433 with patients in a clinical environment.

Mitigation of nitrogen mustard mediated skin injury by a novel indomethacin bifunctional prodrug

Nitrogen mustard (NM) is a bifunctional alkylating agent that is highly reactive in the skin causing extensive tissue damage and blistering. In the present studies, a modified cutaneous murine patch model was developed to characterize NM-induced injury and to evaluate the efficacy of an indomethacin pro-drug in mitigating toxicity. NM (20μmol) or vehicle control was applied onto 6mm glass microfiber filters affixed to the shaved dorsal skin of CD-1 mice for 6min. This resulted in absorption of approximately 4μmol of NM. NM caused localized skin damage within 1 d, progressing to an eschar within 2-3 d, followed by wound healing after 4-5 d. NM-induced injury was associated with increases in skin thickness, inflammatory cell infiltration, reduced numbers of sebocytes, basal keratinocyte double stranded DNA breaks, as measured by phospho-histone 2A.X expression, mast cell degranulation and increases in inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Wound healing was characterized by epidermal hyperplasia and marked increases in basal cells expressing proliferating cell nuclear antigen. A novel indomethacin-anticholinergic prodrug (4338) designed to target cyclooxygenases and acetylcholinesterase (AChE), was found to markedly suppress NM toxicity, decreasing wound thickness and eschar formation. The prodrug also inhibited mast cell degranulation, suppressed keratinocyte expression of iNOS and COX-2, as well as markers of epidermal proliferation. These findings indicate that a novel bifunctional pro-drug is effective in limiting NM mediated dermal injury. Moreover, our newly developed cutaneous patch model is a sensitive and reproducible method to assess the mechanism of action of countermeasures.

Antifungal activity of chitooligosaccharides against the dermatophyte Trichophyton rubrum

Antifungal activity against the dermatophytic fungus Trichophyton rubrum by a well-characterized chitooligosaccharides (COS) sample, hydrolyzed using a recombinant chitosanase, was investigated in vitro and in vivo. The minimum inhibitory concentration (MIC) of COS ranged between 0.25 and 0.50%, which was measured using a microdilution method. Analysis of inhibition rates using an agar diffusion method showed that treatment with 0.5% and 1% COS significantly suppressed T. rubrum cell growth (p<0.05 and p<0.01, respectively, in comparison with untreated control). Morphological changes and structural alterations of cells were observed by TEM. In vivo efficacy of COS in treatment of T. rubrum dermatophytosis was evaluated using a guinea pig model. Skin lesion scores revealed a strong, dose-dependent therapeutic effect of COS. The 5% COS group showed a reduction of skin lesions even greater than that of the positive control group treated with 1% fluconazole (FCZ). Histological analysis revealed no inflammation or tissue destruction in the groups treated with 5% COS or 1% FCZ. Hyperkeratosis was also observed, perhaps resulting from a defensive response of the tissue cells to COS. The findings indicate that COS has excellent potential for development of novel antifungal drugs for clinical treatment/remission of dermatophytoses.

Healthcare workers' hand microbiome may mediate carriage of hospital pathogens

One function of skin microbiota is to resist colonization and infection by external microorganisms. We sought to detect whether the structure of the hand microbiota of 34 healthcare workers (HCW) in a surgical intensive care unit mediates or modifies the relationship between demographic and behavioral factors and potential pathogen carriage on hands after accounting for pathogen exposure. We used a taxonomic screen (16S rRNA) to characterize the bacterial community, and qPCR to detect presence of Staphylococcus aureus,Enterococcus spp., methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans on their dominant hands. Hands were sampled weekly over a 3-week period. Age, hand hygiene, and work shift were significantly associated with potential pathogen carriage and the associations were pathogen dependent. Additionally, the overall hand microbiota structure was associated with the carriage of potential pathogens. Hand microbiota community structure may act as a biomarker of pathogen carriage, and modifying that structure may potentially limit pathogen carriage among HCW.

Short term study of human skin irritation by single application closed patch test: assessment of four multiple emulsion formulations loaded with botanical extracts

BACKGROUND

Assessment of skin irritation potential is a major concern in safety assessment of cosmetics, when long-term use of these products are expected. Non-invasive bioengineering probes have been used previously to measure skin irritation potential of cosmetic ingredients.

OBJECTIVES

Experimentation carried out to weigh up the skin irritation potential of four multiple emulsion formulations via visual and non-invasive measurements. Immediate effects of formulations and comparison of two assessment techniques were also tried to establish.

METHODS

Four multiple emulsion formulations one control (without botanical active) and three containing the functional botanical actives plus additives were tested in this study using the following techniques: transepidermal water loss (TEWL), COLIPA visual scoring method (CVSM), Mexameter MPA 5 (Courage + Khazaka, Germany) and capacitance [Corneometer MPA 5 (Courage + Khazaka, Germany)]. Visual examination and non-invasive measurements were performed at baseline and after 24 h. The formulations were applied on the forearm of 12 healthy volunteers of same sexes aged 20-25 years.

RESULTS

We found that none of the formulation produced irritation both on visual and instrumental evaluation. However, formulations MeB and MeC have comparable immediate effects on dryness, erythema, melanin and TEWL. Formulation MeC produced more effective results on different parameters, may be due to synergistic effect of two extracts, while MeA failed to produce any immediate effects on skin parameters. Moreover results of both assessment methods are parallel to each other.

CONCLUSIONS

None of the formulation produce irritant effects, barrier impairment effects or immediate effects except for the formulation MeC which produced appreciable results than other formulations but statistically these results were insignificant (p > 0.05). Based on these results, it could be concluded that formulations may be implied safely as skin rejuvenating candidates.

Skin reactions in a phase 3 study of a testosterone topical solution applied to the axilla in hypogonadal men

OBJECTIVE

Axiron (testosterone topical solution 2%) is an approved topical testosterone replacement therapy applied to the axilla. The axilla is a novel application site for testosterone replacement therapy, with differences in skin structure and exposure that could impact the type and/or severity of skin reactions observed with testosterone topical solution 2%. We therefore present a detailed description of data from a pivotal clinical trial regarding the incidence, time of onset, duration, and severity of patient-reported skin reactions as well as visual assessments made by investigators and rated using Draize scoring. *Axiron is a trademark of Eli Lilly and Company, Indianapolis, IN, USA.

METHODS

Data were analyzed from a multinational, open-label, clinical study in which a 2% testosterone topical solution was applied to the axilla in hypogonadal men. The primary study was for 120 days (N = 155) with a 60-day extension that evaluated skin safety (N = 71). At each visit investigators asked patients about adverse skin reactions (including those occurring between study visits); visually assessed the application site; and graded observed instances of erythema or edema using Draize scoring (rated from 0 to 4).

RESULTS

Application-site irritation following study drug application was the most commonly reported event (n = 12 patients) and was generally mild (n = 11; moderate, n = 1) in severity. Application-site irritation did not increase in severity over time and led to only one discontinuation. Erythema was the second most common patient-reported skin reaction (n = 10 patients) and was also generally mild (n = 9; moderate, n = 1). Draize scoring rated all directly observed cases of erythema as grade 1 (very slight, 6 patients) or grade 2 (well-defined, two patients), and identified two instances of erythema not reported by patients. Erythema was typically transient, and in most cases resolved without interruption of therapy. Three cases of edema were reported by patients, and two of these were also identified by visual inspection; all cases of edema occurred in conjunction with erythema. Two cases of acne (facial, shoulders) and one of folliculitis (scalp) were also reported.

CONCLUSIONS

Skin reactions were observed in a minority of patients, were mild or at most moderate in severity, and seldom led to discontinuation.