Occurrence of alkyl glucosides in rinse-off cosmetics marketed as hypoallergenic or for sensitive skin

Rinse-off cosmetic products, primarily shampoos, are frequently implicated in the onset of allergic contact dermatitis (ACD) caused by alkyl glucosides (AGs). AGs are increasingly popular surfactants and known contact allergens. Glucoside-induced ACD was most frequently observed with shampoos and skin-cleansing products in both consumer and occupational settings. Thereby, studies have shown that atopic individuals are the most susceptible to ACD. Also, several investigations have indicated that individuals with sensitive skin might be more prone to skin allergies. This is why the presence of AGs was investigated in shampoos and body cleansers marketed as hypoallergenic or for sensitive skin. For this purpose, the website of Amazon.com was surveyed. Four groups of cosmetics were obtained by using the following keywords: "hypoallergenic shampoo for adults," "sensitive skin shampoo for adults," "hypoallergenic body cleanser for adults," and "sensitive skin body cleanser for adults." The first 30 best-selling cosmetics in each group were investigated for the presence of AGs, by analyzing the product information pages. The results showed that as much as 56.7% of hypoallergenic shampoos contained AGs, as ingredients, whereas the percentage was somewhat lower for other product categories. Even though decyl and lauryl glucoside were nearly ubiquitously used AGs in cosmetics over the past decade, the most commonly present AG in our analysis was coco-glucoside. The results of this study indicated a necessity to include coco-glucoside in the baseline series of patch testing allergens. Industry, regulators, and healthcare providers should be made aware of the frequent presence of AGs in rinse-off cosmetic products marketed as hypoallergenic or for sensitive skin to ensure the safety and well-being of consumers and patients.

Untangling Associations of Microbiomes of Pregnancy and Preterm Birth

This review illuminates the complex interplay between various maternal microbiomes and their influence on preterm birth (PTB), a driving and persistent contributor to neonatal morbidity and mortality. Here, we examine the dynamics of oral, gastrointestinal (gut), placental, and vaginal microbiomes, dissecting their roles in the pathogenesis of PTB. Importantly, focusing on the vaginal microbiome and PTB, the review highlights (1) a protective role of Lactobacillus species; (2) an increased risk with select anaerobes; and (3) the influence of social health determinants on the composition of vaginal microbial communities.

Effect of Plant Essential Oil Formulations on Bemisia tabaci MEAM1 (Gennadius) and Its Parasitoid Eretmocerus hayati (Zolnerowich and Rose)

Silverleaf whitefly (SLW), Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), consists of genetically diverse species known to cause significant destruction in many crops around the world. Nowadays, synthetic insecticides are a key component in the management of this pest. However, they also come with disadvantages, such as environmental pollution, pest resistance and recurrence, and toxicity to pollinators and natural enemies. Essential oils from aromatic plants and biocontrol agents may provide a new and safe alternative to synthetic chemicals. In this study, we assessed the lethal impact of three new plant essential oil formulations (referred to as F1, F2, and F3) against the developmental stages of B. tabaci and its parasitoid Eretmocerus hayati (Zolnerowich and Rose) (Hymenoptera: Aphelinidae). The tested formulations consisted of combinations of mustard oil and different surfactants. The formulations were effective against the eggs and nymphal stages of B. tabaci. At the highest concentration assessed (1.23%), F1 was the most effective formulation against the eggs, resulting in 85% mortality, whereas F2 was most effective against the nymphs (92.5% and 88.3% mortality for the young and old nymphs, respectively). However, adult mortality rates were below 40% for all the tested formulations. The range of median lethal concentration (LC50) values was between 0.65 and 1.05% for B. tabaci. The side effects of the three formulations were assessed against E. hayati, treated as parasitized nymphs of B. tabaci. At the highest tested concentration (1.23%), F2 and F3 resulted in 80% and 70% mortality of the parasitoids, respectively (classified as moderately or slightly harmful according to the IOBC), whereas F1 resulted in 17.5% mortality. As F1 was effective against SLW with minimal effects on the parasitoid, it is the most suitable formulation of those tested for use in an integrated pest management (IPM) program targeting the younger life stages of B. tabaci.

Glycolipids mimicking biosurfactants of the synthetic origin as new immunomodulating and anticandidal derivatives

The immunobiological effectivity of glycolipids mimicking biosurfactants of the synthetic origin was followed up using macrophages cell line RAW264.7. These derivatives with different number of mannose units connected glycosidically or through triazole linker, and all having octyl aglycone, were evaluated with respect to their structure - immunomodulation activity relationship. This comparative study showed that the structural variations of the selected derivatives influenced the immunobiological cell behaviour as concerned pro-inflammatory TNF-α, IL-6, IL-1α, IL-17, IL-12 and anti-inflammatory IL-10 cytokines production and enhancement of RAW264.7 cell proliferation. The derivatives with mannose units linked through triazole linkers exerted in some cases stronger immunomodulative potency than (di)mannosides. On the other hand, a presence of triazole linker is a less favourable for an effective candidacidal activity as determined by in vitro using Candida albicans biofilm. The design of new defined immunomodulating formulas of the synthetic origin as possible antifungal agents and prospective participants in drug delivery systems may be of interest.

Structural Racism and Adverse Pregnancy Outcomes Through the Lens of the Maternal Microbiome

Microbiome science offers a glimpse into personalized medicine by characterizing health and disease states according to an individual's microbial signatures. Without a critical examination of the use of race as a variable, microbiome studies may be susceptible to the same pitfalls as other areas of science grounded in racist biology. We will examine the use of race as a biological variable in pregnancy-related microbiome research. Emerging data from studies that investigate the intestinal microbiome in pregnancy suggest strong influence of a poor diet on adverse pregnancy outcomes. Differences in the vaginal microbiome implicated in adverse pregnancy outcomes are frequently attributed to race. We review evidence that links systemic racism to pregnancy health outcome differences with a focus on the vaginal and intestinal microbiomes as well as diet. We also review how structural racism ultimately contributes to inequitable access to healthy food and higher risk environmental exposures among pregnant people of lower socioeconomic status and exacerbates common pregnancy comorbidities.

Preparation and In Vitro Characterization of Alkyl Polyglucoside-Based Microemulsion for Topical Administration of Curcumin

The skin is a complex and selective system from the perspective of permeability to substances from the external environment. Microemulsion systems have demonstrated a high performance in encapsulating, protecting and transporting active substances through the skin. Due to the low viscosity of microemulsion systems and the importance of a texture that is easy to apply in the cosmetic and pharmaceutical fields, gel microemulsions are increasingly gaining more interest. The aim of this study was to develop new microemulsion systems for topical use; to identify a suitable water-soluble polymer in order to obtain gel microemulsions; and to study the efficacy of the developed microemulsion and gel microemulsion systems in the delivery of a model active ingredient, namely curcumin, into the skin. A pseudo-ternary phase diagram was developed using AKYPO^® SOFT 100 BVC, PLANTACARE^® 2000 UP Solution and ethanol as a surfactant mix; caprylic/capric triglycerides, obtained from coconut oil, as the oily phase; and distilled water. To obtain gel microemulsions, sodium hyaluronate salt was used. All these ingredients are safe for the skin and are biodegradable. The selected microemulsions and gel microemulsions were physicochemically characterized by means of dynamic light scattering, electrical conductivity, polarized microscopy and rheometric measurements. To evaluate the efficiency of the selected microemulsion and gel microemulsion to deliver the encapsulated curcumin, an in vitro permeation study was performed.

Preterm birth is associated with xenobiotics and predicted by the vaginal metabolome

Spontaneous preterm birth (sPTB) is a leading cause of maternal and neonatal morbidity and mortality, yet its prevention and early risk stratification are limited. Previous investigations have suggested that vaginal microbes and metabolites may be implicated in sPTB. Here we performed untargeted metabolomics on 232 second-trimester vaginal samples, 80 from pregnancies ending preterm. We find multiple associations between vaginal metabolites and subsequent preterm birth, and propose that several of these metabolites, including diethanolamine and ethyl glucoside, are exogenous. We observe associations between the metabolome and microbiome profiles previously obtained using 16S ribosomal RNA amplicon sequencing, including correlations between bacteria considered suboptimal, such as Gardnerella vaginalis, and metabolites enriched in term pregnancies, such as tyramine. We investigate these associations using metabolic models. We use machine learning models to predict sPTB risk from metabolite levels, weeks to months before birth, with good accuracy (area under receiver operating characteristic curve of 0.78). These models, which we validate using two external cohorts, are more accurate than microbiome-based and maternal covariates-based models (area under receiver operating characteristic curve of 0.55-0.59). Our results demonstrate the potential of vaginal metabolites as early biomarkers of sPTB and highlight exogenous exposures as potential risk factors for prematurity.

A review on the synthesis of bio-based surfactants using green chemistry principles

OBJECTIVES

With increasing awareness of the potential adverse impact of conventional surfactants on the environment and human health, there is mounting interest in the development of bio-based surfactants (which are deemed to be safer, more affordable, are in abundance, are biodegradable, biocompatible and possess scalability, mildness and performance in formulation) in personal care products.

METHOD

A comprehensive literature review around alkyl polyglucosides (APGs) and sucrose esters (SEs) as bio-based surfactants, through the lens of the 12 green chemistry principles was conducted. An overview of the use of bio-based surfactants in personal care products was also provided.

RESULTS

Bio-based surfactants are derived primarily from natural sources (i.e. both the head and tail molecular group). One of the more common types of bio-based surfactants are those with carbohydrate head groups, where alkyl polyglucosides (APGs) and sucrose esters (SEs) lead this sub-category. As global regulations and user mandate for sustainability and safety increase, evidence to further support these bio-based surfactants as alternatives to their petrochemical counterparts is advantageous. Use of the green chemistry framework is a suitable way to do this. While many of the discussed principles are enforced industrially, others have only yet been applied at a laboratory scale or are not apparent in literature.

CONCLUSION

Many of the principles of green chemistry are currently used in the synthesis of APGs and SEs. These and other bio-based surfactants should, therefore, be considered suitable and sustainable alternatives to conventional surfactants. To further encourage the use of these novel surfactants, industry must make an effort to implement and improve the use of the remaining principles at a commercial level.

Safety Assessment of Ethers and Esters of Ascorbic Acid as Used in Cosmetics

The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the safety of 7 ethers and esters of ascorbic acid, which collectively function as antioxidants, skin-conditioning agents, skin protectants, fragrance ingredients, and skin bleaching agents in cosmetic products. The Panel reviewed relevant data relating to the safety of these ingredients, and concluded that the ethers and esters of ascorbic acid are safe in the present practices of use and concentration, as described in this safety assessment.

Patch testing with glucosides: The North American Contact Dermatitis Group experience, 2009-2018

BACKGROUND

Alkyl glucosides are nonionic surfactants that are increasingly used in personal care products.

OBJECTIVE

To characterize positive patch test reactions to decyl glucoside (5% petrolatum, tested 2009-2018) and lauryl glucoside (3% petrolatum, tested 2017-2018).

METHODS

Retrospective analysis of patients tested by the North American Contact Dermatitis Group.

RESULTS

Of 24,097 patients patch tested to decyl and/or lauryl glucoside, 470 (2.0%) had positive reactions. Compared with glucoside-negative patients, glucoside-positive patients had higher odds of occupational skin disease (13.4% vs 10.1%; P = .0207), history of hay fever (38.5% vs 31.6%; P = .0014), atopic dermatitis (39.0% vs 28.6%; P < .0001), and/or asthma (21.8% vs 16.5%; P = .0023). Most glucoside reactions (83.9%) were currently relevant. The most common source was personal care products (63.0%), especially hair products (16.5%) and skin cleansers (15.2%). Of 4933 patients tested to decyl and lauryl glucoside, 134 (2.7%) were positive to 1 or both; 43.4% (43 of 99) of decyl-positive patients were also positive to lauryl glucoside and 55.1% (43/78) of lauryl glucoside patients were also positive to decyl glucoside.

LIMITATIONS

The cohort predominantly reflects a referral population, and follow-up after testing was not captured.

CONCLUSION

Glucoside positivity occurred in 2.0% of the tested patients. Reactions were often clinically relevant and linked to personal care products. Cross-reactivity was >40%.

Surface Properties of Alkyldi(oxyethylene) β-D-Maltoside

A series of nonionic disaccharide-based surfactants alkyldi(oxyethylene) β-d-maltosides (4a-4h, n = 6-16) were synthesized, and their physicochemical properties were further investigated. Six β-D-maltosides (4c-4h, n = 8-16) exhibited a fan-shaped texture feature, whereas hexyldi(oxyethylene) β-D-maltoside (4a) had the strongest hygroscopicity. Owing to the incorporation of the hydrophilic dioxyethyl spacer (-(OCH₂CH₂)₂-), the related water solubility improved significantly. Tetradecyldi(oxyethylene) β-D-maltoside (4g) had good water solubility, whereas hexadecyldi(oxyethylene) β-D-maltoside (4h) had weak water solubility. Meanwhile, the surface tension of β-D-maltosides (4a-4g, n = 6-14) had a decreasing tendency with increasing the alkyl chain length, whereas 4g had the best surface activity. Furthermore, decyldi(oxyethylene) β-D-maltoside (4e) had the best foaming ability and foam stability. Dodecyldi(oxyethylene) β-D-maltoside (4f) had the best emulsifying property in the rapeseed oil/water system. In contrast, both ammonium dodecyl sulfate (NH₄DS)/4f and cetyltrimethylammonium chloride (CTAC)/4f binary surfactant systems showed a synergistic effect in surface activity because the C_CMC/CMC^id_mix was <1. NaCl impacted the surface activity of the aqueous 4f solution through salt-surfactant synergistic effects. The results showed that such surfactants should have potential applications in the related field in the future.

Impact of trends in new and emerging contact allergens

Allergic contact dermatitis represents a T cell-mediated, delayed-type hypersensitivity response to exogenous agents. While allergic contact dermatitis is one of the most common causes of skin disease encountered by dermatologists, emerging trends within the field are in constant flux, as influenced by ever-changing industry practices and evolving consumer behaviors. Although certain allergens continue to predominate, new chemicals are frequently being introduced, thus shifting the pattern of allergen exposure and sensitization. This review examines the impact of trends in new and emerging contact allergens, with particular attention to clinical contexts in which these agents may be encountered. In addition, we offer a working knowledge of these allergens’ characteristics, sources, and relevance, while outlining recommendations to accurately evaluate, diagnose, and provide appropriate counseling for these diseases.

Análisis del rótulo y características de los jabones utilizados en la piel del recién nacido

Objetivo:

Analizar la información del rótulo, y las características físicas y fisicoquímicas de los jabones usados en recién nacidos (RN).

Método:

Estudio cuantitativo y descriptivo de 17 jabones comercializados en San Pablo, Brasil. Se analizó la información del rótulo (tensioactivos, pruebas de seguridad y descripción del valor de pH), y las características físicas (color y fragancia) y fisicoquímicas (valor de pH) del producto; las dos últimas, en laboratorio.

Resultados:

Se identificaron 27 tipos de tensioactivos: 70,3% (n=19) aniónicos, 18,5% (n=5) anfóteros y 11,1% (n=3) no iónicos. El 37% (n=10) tuvo un potencial moderado de irritación. En cuanto a las pruebas de seguridad, la mayoría de las formulaciones (94,1%) citó “dermatológicamente probado”. Sólo 42% citó “oftalmológicamente probado”. La translucidez estuvo presente en 23,5% (n=4) de los jabones. Todas las formulaciones presentaron fragancia. El promedio más alto de valor de pH fue de jabones en barra tradicionales (9,94 DE 0,81).

Conclusión:

Las formulaciones analizadas indicaron un potencial de irritación bajo o moderado. Cuatro jabones líquidos y uno en barra combinados tuvieron valores cercanos a los del pH de la piel del RN, y mostraron ser adecuados para la homeostasis de la barrera cutánea. Aunque las formulaciones citaron “dermatológicamente probado”, no todas citaron “oftalmológicamente probado”. Este estudio proporciona elementos para seleccionar un jabón adecuado para el RN.

From water-rich to oil-rich gelled non-toxic microemulsions

Gelled non-toxic microemulsions have great potential in transdermal drug delivery: the microemulsion provides an optimum solubilizing capacity for drugs and promotes drug permeation through the skin barrier, while the gel network provides mechanical stability. We have formulated such a gelled non-toxic microemulsion consisting of H2O - isopropyl myristate (IPM) - Plantacare 1200 UP (technical-grade alkyl polyglucoside with an average composition of C12G1.4) - 1,2-octanediol in the presence of the low molecular weight gelator (LMWG) 1,3:2,4-dibenzylidene-d-sorbitol (DBS) at an oil-to-water ratio of φ = 0.50. The study at hand aimed to develop gelled non-toxic microemulsions that can contain both oil- and water-soluble drugs and are either water- or oil-based, depending on the application. To accomplish this, we varied the oil-to-water ratio from being water-rich to oil-rich, i.e. 0.2 ≤ φ ≤ 0.8. Phase studies were carried out along the middle phase trajectory, and a suitable LMWG was identified for all φ-ratios. Electrical conductivity measurements showed that the structure can be tuned from water- to oil-continuous by adjusting the amount of 1,2-octanediol and φ-ratios. The existence of the gel network was visualized by freeze-fracture electron microscopy (FFEM) at three different φ-ratios. We found that all systems from φ = 0.35 to φ = 0.80 form strong gels with nearly the same rheological behavior, while the system with φ = 0.20 is a much weaker gel. We attribute this behavior on the one hand to the microemulsion microstructure and on the other hand to the solvent-dependent gelation properties of DBS, which can be described by the Hansen solubility parameters (HSPs).

Comparison between HET-CAM protocols and a product use clinical study for eye irritation evaluation of personal care products including cosmetics according to their surfactant composition

The hen's egg test on chorioallantoic membrane (HET-CAM) is one of the most frequently used alternative tests for prediction of ocular irritation of cosmetic products. There are different HET-CAM protocols widely accepted, but there is no information about which of the protocols better correlates with the results obtained in product use clinical study under the conditions of use. Two Fix Time Methods (FTM) -Lüepke and the ICCVAM guideline - and two Reaction Time Methods (RTM) -ECVAM DBALM Prot. No. 47 and No. 96- were employed to test 18 cosmetic products. Simultaneously, they were evaluated by an ophthalmological clinical test. A unified classification system was used, and products were classified into four irritation levels: non-irritant, weak, moderate and severe irritant. The duration of use (rinse-off or leave-on), and the concentration and type of surfactants were taken into account in the analysis. All the products that were classified as non-irritant by any HET-CAM protocols were also safe in the product use clinical study. The product that was found to be non-safe in the product use clinical evaluation was also unsuitable by most of the HET-CAM protocols. These results were employed to develop an algorithm that allows selecting the appropriate HET-CAM protocol for each type of product to be tested.

Synthesis and property of alkyl dioxyethyl α-D-xyloside

Due to the inherent defects of the long alkyl chain in the related hydrophilicity and water solubility, alkyl α-D-xylosides (7) had hardly the practical application as sugar-based surfactants and should be reconstructed to obtain alkyl dioxyethyl α-D-xylosides (5) with dioxyethylene fragment (-(OCH2CH2)2-)) as the hydrophilic spacer to increase the related TPSA value. With D-xylose as the raw material, 1,2-cis alkyl dioxyethyl α-D-xylosides (5a-5f, n = 6-12) were stereoselectively synthesized. Their physicochemical properties including water solubility, surface tension, foamability, emulsification, thermotropic liquid crystal, and hygroscopicity had been investigated. Their water solubility was found to decrease gradually whereas their calculated HLB numbers were 14.72 → 11.67 (n = 6 → 12) with increasing alkyl chain length (n). Dodecyl dioxyethyl α-D-xyloside (5f) had not water solubility because the HLB number was low. Furthermore, their CMC values decreased with increasing the alkyl chain length, and the CMC value of decyl dioxyethyl α-D-xyloside (5e) was as low as 9.21 × 10-5 mol·L-1. Octyl dioxyethyl α-D-xyloside (5c) had the lowest surface tension (27.25 mN·m-1) at the CMC. Both of nonyl and decyl dioxyethyl α-D-xylosides (5d & 5e) possessed good foaming power and foam stability. Decyl dioxyethyl α-D-xyloside (5e) had the strongest emulsifying property either in the toluene/water system or in the octane/water system. Nonyl dioxyethyl α-D-xylosides (5d) had the most stylish SA texture. Hexyl dioxyethyl α-D-xyloside (5a) possessed the strongest hygroscopicity. Therefore, the alkyl dioxyethyl α-D-xylosides as a class of novel sugar-based surfactants will be widely considered as promising candidates for various practical applications.

The science behind wet wipes for infant skin: Ingredient review, safety, and efficacy

In the diapered area, the continuous exposure to excess moisture and irritants from urine and feces weakens the stratum corneum, making the skin more susceptible to irritation. The use of wet wipes for infants (baby wipes) is a common practice to clean skin after urine or a bowel movement, and this practice even extends to cleaning the hands and face, resulting in repeated daily use. Therefore, ensuring that baby wipes contain ingredients that are safe and mild on skin is important to help minimize skin irritation and discomfort. While disposable baby wipes have been shown to be effective and gentle at cleaning infant skin, even the skin of premature infants, there is growing public concern regarding their safety and tolerability. Not all products are made the same, as differences exist in manufacturing processes, ingredients, materials, safety, and quality testing. Therefore, it is important that healthcare professionals have accessible evidenced-based information on the safety and tolerability of common ingredients found in baby wipes to optimally educate their patients and families. Herein, we provide a review on best practices for ingredient selection, safety, and efficacy of baby wipes.

Gelled non-toxic microemulsions: phase behavior & rheology

Bicontinuous microemulsions gelled with a low molecular weight gelator have been shown to be an orthogonally self-assembled system. With the mechanical stability provided by the gel network, gelled non-toxic bicontinuous microemulsions have the potential to be an efficient transdermal drug delivery carrier. However, up to now no suitable system has been formulated for transdermal drug delivery. To fill this gap, we formulated and characterized a gelled non-toxic bicontinuous microemulsion suitable for the mentioned application. Starting from a previously studied scouting system, namely, H2O-n-octane-n-octyl β-d-glucopyranoside (β-C8G1)-1-octanol, the co-surfactant and the oil were replaced by non-toxic components. Subsequently, the expensive pure surfactant was replaced by cheap technical-grade surfactants (Plantacare® series) to make the system economical. Having formulated the non-toxic microemulsion H2O-IPM-Plantacare 1200 UP-1,2-octanediol, three low molecular weight gelators were studied with regard to the gelation of both the scouting system and the non-toxic system. The chosen gelators were 12-hydroxyoctadecanoic acid (12-HOA), 1,3:2,4-dibenzylidene-d-sorbitol (DBS), and N,N'-dibenzoyl-l-cystine (DBC). We found that only DBS gels the non-toxic microemulsion. The gelled non-toxic bicontinuous microemulsion H2O-IPM-Plantacare 1200 UP-1,2-octanediol was characterized with oscillatory shear rheometry and small-angle neutron scattering (SANS) at a DBS concentration of 0.3 wt% to verify that the system is indeed a gel and that the microstructure of the microemulsion is not altered by the gel network.

Water Solubility and Surface Property of Alkyl Di-/Tri-/Tetraoxyethyl β-d-Xylopyranosides

Alkyl di-/tri-/tetraoxyethyl β-d-xylopyranosides as derivatives of alkyl xylosides are a class of non-ionic sugar-based surfactants. They were stereoselectively synthesized by the Helferich method. Their properties including hydrophilic-lipophilic balance number, water solubility, surface property, foam property, emulsifying property, and thermotropic liquid crystal property were mainly investigated. The results showed that their water solubility decreased with increasing the alkyl chain length and increasing the number of the oligooxyethyl fragment. The critical micelle concentration had a monotonous decreasing trend with increasing the alkyl chain length. Nonyl di-/tri-/tetraoxyethyl β-d-xylopyranosides [-(OCH₂CH₂)_m-, where m = 2, 3, and 4] exhibited the most excellent foaming ability and foam stability. In the n-octane/water system, dodecyl tetraoxyethyl β-d-xylopyranosides and tetradecyl tetraoxyethyl β-d-xylopyranosides had the strongest emulsion ability. In addition, some alkyl di-/tri-/tetraoxyethyl β-d-xylopyranosides had thermotropic liquid crystal properties. Such sugar-based surfactants, alkyl di-/tri-/tetraoxyethyl β-d-xylopyranosides, will be expected to develop for a variety of practical application.

Preclinical Evaluation of Tolerability of a Selective, Bacteriostatic, Locally Active Vaginal Formulation

BACKGROUND

Polybactum (Effik International, Brussels, Belgium) is a vaginal mucoadhesive product (medical device) designed to form a film that acts as a mechanical barrier with the aim of inhibiting colonization by specific pathogens. It contains polycarbophil, a bioadhesive agent, and lauryl glucoside (LG), a nonionic surfactant that reinforces the barrier effect through its tensioactive properties.

OBJECTIVE

To assess the local safety profile, tolerability, and efficacy of Polybactum formulations.

METHODS

The following studies were performed on 3 Polybactum formulations: 2 ovules (Type 1: LG 0.04% and Type 2: LG 0.1%) and 1 gel formulation. Bacteriologic tests assessing the effects on normal vaginal flora and pathogens; in vitro and in vivo tests designed to assess cytotoxicity, as well as irritant and sensitizing potentials; biocompatibility, barrier, residence time, and absorption tests using reconstituted human vaginal epithelium were performed.

RESULTS

Polybactum is a selective bacteriostatic agent that is active against Streptococcus agalactiae and Gardnerella vaginalis while sparing normal vaginal flora; that is, Lactobacillus spp. It had no cytotoxic, irritant, and sensitizing effects nor did it impair barrier and fence functions of the vaginal epithelium. The Type 1 ovule showed film-forming properties in vitro. Finally, LG absorption through reconstituted human vaginal epithelium was negligible, ruling out the risk for possible systemic toxicity.

CONCLUSIONS

This favorable preclinical profile is encouraging and supports clinical studies on Polybactum Type 1 ovules for the prevention and management of recurring bacterial vaginosis.

Isobornyl acrylate: an impurity in alkyl glucosides

CONTEXT

Alkyl glucosides and alkyl poly-glucosides are widely used as wetting agents, surfactants and emulsifiers in several industrial and cosmetic products. They are known as well-tolerated and are usually added to the primary surfactants in order to reduce the irritating potential of the main foaming agents.

OBJECTIVE

Recently, some authors suggested that allergic contact dermatitis to alkyl glucosides might be more frequent than suspected. On the other hand, the chemical structures of glucosides do not show potentially allergenic chemical groups or strongly polarized structures. The aim of our study is to investigate alkyl glucosides carrying out a detailed chemical analysis on samples of raw materials to identify potentially allergenic impurities or by-products contained in commercial samples of alkyl glucosides.

MATERIALS AND METHODS

We chemically analyzed samples of cocoyl glucoside, decyl glucoside and lauryl glucoside by three different analytical methods, in order to identify any undesired or polluting substances.

RESULT

In each of the three samples, we detected the presence of isobornyl acrylate. Its approximate content in the tested samples is 500 ng/g of the product.

DISCUSSION

Isobornyl acrylate is not used in the synthesis of alkyl glucosides, but as a plasticizer in many plastic materials. It can be easily released to materials flowing over these surfaces when they have high extraction power, as glucosides.

CONCLUSION

Isobornyl acrylate may play a role as hidden allergen, in the form of an impurity collected during the industrial process, explaining some cases of allergic reaction to alkyl glucosides.

Health impact of bioaccessible metal in lip cosmetics to female college students and career women, northeast of China

Actual measure-based studies have estimated ingestion rate of moderate and high daily use to female college students and career women in northeast of China. Sequential extraction analyses showed that total bioaccessible metals concentration in lipstick ranged from 2.103 to 31.103 μg/g and in lip balm ranged from 0.100 to 3.716 μg/g. The relationship between total bioaccessible metal concentrations and the cost of lip cosmetics showed a negative correlation. Lead was detected in all 30 products (100%), with an average concentration of 0.346 for lip balm and 0.407 μg/g for lipstick. With the exception of chromium content in three lipsticks, the estimated exposure in female college students and career women to target metals via lipstick and lip balm ingestion (calculated for moderate and high use) were much lower than the acceptable reference limits. The findings strongly emphasize the need to focus on the health risk of lip balm.

Formulation of solid lipid nanoparticles (SLN): the value of different alkyl polyglucoside surfactants

Alkyl polyglycosides (APGs) represent a group of nonionic tensides with excellent skin compatibility. Thus they seem to be excellent stabilizers for lipid nanoparticles for dermal application. To investigate this, different APGs were selected to evaluate their influence on the formation and characteristics of solid lipid nanoparticles (SLN). Contact angle analysis of the aqueous solutions/dispersions of the APGs on cetyl palmitate films revealed good wettability for all APG surfactants. Cetyl palmitate based SLN were prepared by hot high pressure homogenization and subjected to particle size, charge and inner structure analysis. 1% of each APG was sufficient to obtain SLN with a mean size between 150 nm and 175 nm and a narrow size distribution. The zeta potential in water was ∼ -50 mV; the values in the original medium were distinctly lower, but still sufficient high to provide good physical stability. Physical stability at different temperatures (5°C, 25°C and 40°C) was confirmed by a constant particle size over an observation period of 90 days in all dispersions. In comparison to SLN stabilized with classical surfactants, e.g., Polysorbate, APG stabilized SLN possess a smaller size, improved physical stability and contain less surfactant. Therefore, the use of APGs for the stabilization of lipid nanoparticles is superior in comparison to classical stabilizers. Further, the results indicate that the length of the alkyl chain of the APG influences the diminution efficacy, the final particle size and the crystallinity of the particles. APGs with short alkyl chain led to a faster reduction in size during high pressure homogenization, to a smaller particle size of the SLN and to a lower recrystallization index, i.e., to a lower crystallinity of the SLN. The crystallinity of the SLN increased with an increase in the alkyl chain length of APGs. Therefore, by using the tested APGs differing in the alkyl chain length, not only small sized and physically stable but also SLN with different sizes and crystallinity can be obtained. An optimized selection of these stabilizers might therefore enable the production of lipid nanoparticles with "tailor-made" properties.