The fabrication and assessment of mosquito repellent cream for outdoor protection.

Mosquito-borne infections like dengue, malaria, chikungunya, etc. are a nuisance and can cause profound discomfort to people. Due to the objectional side effects and toxicity associated with synthetic pyrethroids, N,N-diethyl-3-methylbenzamide (DEET), N,N-diethyl phenylacetamide (DEPA), and N,N-di ethyl benzamide (DEBA) based mosquito repellent products, we developed an essential oil (EO) based mosquito repellent cream (EO-MRC) using clove, citronella and lemongrass oil. Subsequently, a formulation characterization, bio-efficacy, and safety study of EO-MRC were carried out. Expression of Anti-OBP2A and TRPV1 proteins on mosquito head parts were studied by western blotting. In-silico screening was also conducted for the specific proteins. An FT-IR study confirmed the chemical compatibility of the EOs and excipients used in EO-MRC. The thermal behaviour of the best EOs and their mixture was characterized by thermogravimetric analysis (TGA). GC-MS examination revealed various chemical components present in EOs. Efficacy of EO-MRC was correlated with 12% N,N-diethyl benzamide (DEBA) based marketed cream (DBMC). Complete protection time (CPT) of EO-MRC was determined as 228 min. Cytotoxicity study on L-132 cell line confirmed the non-toxic nature of EO-MRC upon inhalation. Acute dermal irritation study, acute dermal dose toxicity study, and acute eye irritation study revealed the non-toxic nature of EO-MRC. Non-target toxicity study on Danio rerio confirmed EO-MRC as safer for aquatic non-target animals. A decrease in the concentration of acetylcholinesterase (AChE) was observed in transfluthrin (TNSF) exposed Wistar rats. While EO-MRC did not alter the AChE concentrations in the exposed animals. Results from western blotting confirmed that Anti-OBP2A and TRPV1 proteins were inhibited in TNSF exposed mosquitoes. Mosquitoes exposed to EO-MRC showed a similar expression pattern for Anti-OBP2A and TRPV1 as the control group. In silico study revealed eight identified compounds of the EOs play significant roles in the overall repellency property of the developed product. The study emphasizes the mosquito repellent activity of EO-MRC, which could be an effective, eco-friendly, and safer alternative to the existing synthetic repellents for personal protection against mosquitoes during field conditions.

Read-across can increase confidence in the Next Generation Risk Assessment for skin sensitisation: A case study with resorcinol.

Historically skin sensitisation risk assessment for cosmetic ingredients was based on animal models, however regulatory demands have led to Next Generation Risk Assessment (NGRA), using data from New Approach Methodologies (NAM) and Defined Approaches (DA). This case study was meant to investigate if the use of resorcinol at 0.2% in a face cream was safe and a maximum use concentration could be defined. The NAM data and DA predictions could not provide sufficient confidence to determine a point of departure (POD). Therefore, the application of read-across was explored to increase the level of confidence. Analogue searches in various tools and databases using "mode of action" and "chemical structural features" retrieved 535 analogues. After refinement by excluding analogues without a defined structure, similar reactivity profile and skin sensitisation data, 39 analogues remained. A final selection was made based on three approaches: expert judgment, chemical similarity or Local Lymph Node Assay data (LLNA). All read-across approaches supported a moderate potency. A POD derived from the LLNA EC3 of 3.6% was determined leading to a favourable NGRA conclusion and a maximum use concentration of 0.36%. This was supported by a traditional risk assessment based on the available animal data for resorcinol.

Prospective, randomized, double-blind assessment of topical bakuchiol and retinol for facial photoageing.

BACKGROUND: Bakuchiol is a phytochemical that has demonstrated cutaneous antiageing effects when applied topically. Early studies have suggested that bakuchiol is a functional analogue of topical retinoids, as both compounds have been shown to induce similar gene expression in the skin and lead to improvement of cutaneous photodamage. No in vivo studies have compared the two compounds for efficacy and side-effects. OBJECTIVES: To compare the clinical efficacy and side-effect profiles of bakuchiol and retinol in improving common signs of cutaneous facial ageing. METHODS: This was a randomized, double-blind, 12-week study in which 44 patients were asked to apply either bakuchiol 0·5% cream twice daily or retinol 0·5% cream daily. A facial photograph and analytical system was used to obtain and analyse high-resolution photographs of patients at 0, 4, 8 and 12 weeks. Patients also completed tolerability assessment questions to review side-effects. During study visits, a board-certified dermatologist, blinded to study group assignments, graded pigmentation and redness. RESULTS: Bakuchiol and retinol both significantly decreased wrinkle surface area and hyperpigmentation, with no statistical difference between the compounds. The retinol users reported more facial skin scaling and stinging. CONCLUSIONS: Our study demonstrates that bakuchiol is comparable with retinol in its ability to improve photoageing and is better tolerated than retinol. Bakuchiol is promising as a more tolerable alternative to retinol.

Moisturizers: A Comparison Based on Allergens and Economic Value.

BACKGROUND: The economic burden of cosmetics, such as moisturizers, has been increasing. Despite the high price of some market moisturizers, there have been no studies evaluating the allergenicity of these products. OBJECTIVE: The aim of this study was to evaluate the potential allergens within moisturizers based on economic value, by analyzing the substances found in moisturizers available online at the largest drugstore chain-CVS Health (CVS Health, Woonsocket, RI). METHODS: In this cross-sectional study, ingredients found in 50 expensive and 50 inexpensive moisturizers were matched with sensitizers within the Core Allergen Series published by the American Contact Dermatitis Society and the North American Contact Dermatitis Group. Student t test was used to compare the mean number of allergens present in each group. A χ test or Fisher exact test, where necessary, was used to compare the rates of specific allergen groups between the expensive and inexpensive products. RESULTS: Twenty-six allergenic substances were present overall in the 100 total products surveyed. The expensive moisturizers averaged significantly more allergens per product (8.28 vs 5.60, P = 0.003) than the inexpensive products. CONCLUSIONS: The sensitizing potential of expensive moisturizers may be higher than that of inexpensive moisturizers. Physicians may counsel cosmetic-induced allergic contact dermatitis (ACD) patients that monetary value is not a suitable proxy for evaluating the risk of ACD.

Assessment of Efficacy and Irritation of Ingenol Mebutate Gel 0.015% Used With or Without Dimethicone Lotion for Treatment of Actinic Keratosis on the Face.

Background: Ingenol mebutate gel 0.015% provides high clearance rates for actinic keratosis (AK) on the face and scalp but causes transient local skin responses (LSRs).

Objective: This study sought to determine whether the application of 1% dimethicone would decrease ingenol mebutate-associated LSRs and/or affect efficacy during the treatment of multiple AKs on the face.

Methods: Ingenol mebutate gel 0.015% was applied for 3 days to two 25 cm2 areas, each containing 3 to 8 AKs on the face of each subject, followed by application of 1% dimethicone lotion in an investigator-blinded manner to one randomly selected AK-containing area until LSRs were no longer present.

Results: In total, 20 subjects were enrolled and completed the study. Topical 1% dimethicone lotion applied during and after treatment of facial AK with ingenol mebutate gel 0.015% reduced mean total LSR scores at days 8 and 15 compared with ingenol mebutate gel only, although the difference was not statistically significant. Efficacy was equivalent between the two treatment arms.

Limitations: The study evaluated a relatively small number of subjects, all of whom were white.

Conclusions: The application of 1% dimethicone following ingenol mebutate gel 0.015% produced a trend toward lower severity of some LSRs, with no difference in efficacy.

J Drugs Dermatol. 2017;16(5):432-436.

Assessment of Irritation and Sensitization Potential of Eight Baby Skin Care Products.

BACKGROUND: Ethnic differences in skin sensitivity suggest that greater emphasis be focused on understanding a product's effect in diverse populations. OBJECTIVE: The irritation and/or sensitization potential of 8 baby skin care products in Indian adults were evaluated using cumulative irritation tests (CIT) and human repeat insult patch testing (HRIPT) protocols. PATIENTS/MATERIALS/METHODS: Healthy males or females aged 18 to 65 years of Indian ethnicity were treated with each of 6 products (cream, hair oil, lotion, body wash, shampoo, and baby soap) using CIT (n = 25) and HRIPT (n = 200). Baby powder and baby oil were evaluated by CIT (n = 25) and HRIPT (n = 107) in separate studies. CITs were conducted over 14 days; HRIPTs were conducted over 10 weeks. RESULTS: In both CIT and HRIPT, most products were considered mild, with no irritation. Baby soap and powder elicited reactions in the HRIPT induction phase, with positive challenge phase reactions (3 subjects), but were affirmed to be nonallergenic in the rechallenge phase. CONCLUSIONS: In these studies, 8 baby skin care products were evaluated by both CIT and HRIPT in Indian adults. The results of the studies indicated that all of the tested products were nonallergenic and nonirritating.

J Drugs Dermatol. 2016;15(10):1244-1248.

Probabilistic Monte Carlo estimation for quantitative exposure assessment of lotion transfer via baby wipes usage.

Unique aspects of childhood exposure to products need childs specific exposure data. This study developed a probabilistic exposure model for lotion transfer to diapered skin through normal use of baby wipes in children up to 48 months of age. Monte Carlo simulations used baby wipe diary data from the US, Germany and the UK, body weight data from the US, and lotion transfer data from single and multiple wipes adjusting for separate diaper changes. The models predicted a declining number of wipes used/day with a reduction in lotion transfer as age and body weight increased. Experimental testing on multiple sequential wipes used on an overlapping area showed a reduction in lotion deposition by 23.9% after the first wipe. Overall, the weighted population average over the approximate diapering period of 0-36 months across the three geographies at 50th, 90th, & 95th percentiles, were between 130, 230, 260 mg/kg/day, respectively, and 150, 270, 310 mg/kg/day depending on whether a reduction due to overlap is implemented. The statistical model represents an effective strategy to determine exposure to baby wipes lotion for exposure based risk assessment.

Assessment of hypoallergenicity of ten skincare products.

Sensitive skin is a common skin complaint frequently associated with skin diseases or adverse reactions to cosmetic products. Manufacturers have produced numerous products targeted for patients with sensitive skin and frequently label these products as being hypoallergenic. This term implies that the product may be less likely to cause an allergic reaction and be better suited for those with sensitive skin. However, there is no federal regulatory definition of this term and products may not have clinical support of their claim. Patch testing ingredients is frequently done to identify potential irritants; however, patch-testing product formulations may provide more realistic expectations about potential skin sensitivity and help support claims of hypoallergenicity. Ten skincare products were assessed for their sensitizing potential and hypoallergenicity in 14 repeat insult patch test clinical studies, involving over 2,000 subjects. In these studies, the products were deemed to be hypoallergenic if there was no evidence of sensitization or allergic reactions. The results from these trials demonstrated that all ten products were well tolerated, showed no sensitization or allergic reactions, and support claims of hypoallergenicity.