Determination of Free Histidine in Complex Hair Care Products with Minimum Sample Preparation Using Cation-Exchange Chromatography and Post Column Derivatization.

In this communication, we describe the first analytical method for the determination of free histidine in hair care products (shampoos and conditioners). Cation-exchange chromatography combined with postcolumn derivatization and fluorimetric detection enabled the accurate (recovery: 83.5-114.8%) and precise (2.4-5.6% RSD) determination of free histidine without matrix interferences at concentration levels down to 1.5 mg kg-1. Real commercially available samples were found to contain the amino acid at levels ranging between 70 and 535 mg kg-1.

Determination of panthenol enantiomers in cosmetic preparations using an achiral-chiral-coupled column HPLC system.

A new high-performance liquid chromatography (HPLC) method for separation and determination of panthenol enantiomers in hair care products was developed. Two types of detectors, low-wavelength ultraviolet (UV) and polarimetric, were used. Optimized conditions consisted of coupled achiral, amino type, and chiral, amylose tris(3,5-dimethylphenylcarbamate), stationary phases, mixture of n-hexane/ethanol (60:40, v/v) as mobile phase under isocratic conditions and flow rate 0.8 cm3 min-1 . The effect of column temperature on retention and resolution of enantiomers was studied. The analysis runtime was 10 minutes, and the average retention times for d- and l-panthenol were 7.10 ±0.1 minutes and 8.21 ±0.2 minutes, respectively. The resolution of enantiomers on coupled achiral-chiral columns was Rs = 2.7. The solid-phase extraction method was employed for extraction and purification of analytes. The validated method was selective, accurate, and linear (R2 > .998) over the concentration range of 0.001 to 1.0 mg cm-3 for both enantiomeric forms. The limits of detection (LOD) and quantitation (LOQ) of each enantiomer were 0.3 and 1.0 µg cm-3 , respectively. The results demonstrated the occurrence of d-panthenol in hair care products.

Late-onset robust curly hair growth in a patient with BRAF-mutated metastatic melanoma responding to dabrafenib.

Development of curly hair has been infrequently described in association with BRAF inhibitors in clinical trials, and usually affects patients between 6 and 24 weeks of therapy. The curly hair is typically preceded by initial hair thinning or even diffuse alopecia. We report herein an occurrence of late-onset robust curly head hair growth in a patient with metastatic melanoma responding well to dabrafenib, without being preceded by hair thinning. The curly hair in our patient developed at 11 months of therapy with dabrafenib. Occurrence of late-onset, robust curly hair might represent a prognostic marker of clinical response to these agents. If our hypothesis is correct, we expect more reports of late-onset, robust curly hair growth with the use of this class of pharmaceuticals. Moreover, newer generations of BRAF inhibitors may expand the armory of hair care products in the future.

The hair tales of women of color in Northern Manhattan: a qualitative analysis.

Introduction: Exposure to endocrine disrupting chemicals (EDCs), such as phthalates, can negatively impact maternal and child health, contributing to impaired fetal growth, preterm birth, and pregnancy complications, as well as increased downstream risks of cardiometabolic disease and breast cancer. Notably, women of color (WOC) are the largest consumers of personal care products, which are a common source of EDC exposure. Methods: The Let's Reclaim Our Ancestral Roots (Let's R.O.A.R) Pilot Study developed an educational intervention delivered during pregnancy to promote reduced use of phthalate-containing hair care products (HCPs). This mixed-methods study included: (1) a quantitative analysis and (2) a qualitative analysis of the educational sessions and the semi-structured focus groups to evaluate the factors that influenced the hair care practices and product choices of WOC at various stages of life, including their current pregnancy (hereafter referred to as the hair journey). During the sessions, participants learned about EDCs (with a focus on phthalates), the unequal burden of exposure for WOC, adverse implications of exposure, and exposure reduction strategies. Focus group sessions provided insight into participants' hair journeys from childhood to the current pregnancy and explored factors during their hair product selection process. All sessions were transcribed and imported into NVivo Version 12 for coding and thematic analysis. Results: A total of 46 individuals were enrolled in the study, and 31 participated in an educational session. This current work synthesizes the qualitative analysis of this study. We identified two important life stages (before and after gaining agency over hair care practices and product choices) and three dominant themes related to HCP use: (1) products that impacted the hair journey, which involved all mentions of hair products, (2) factors that influenced the hair journey, which included individuals or entities that shaped participants' hair experiences, and (3) the relationship between hair and sense of self, where sense of self was defined as the alignment of one's inner and outer beauty. Conclusion: The themes intersected and impacted the participants' hair journey. Cultural integration was a sub-theme that overlapped within the dominant themes and participants discussed the effect of traditions on their hair experiences.

Manipulation of THC Hair Concentrations by Commercially Available Products.

Many drug tests are carried out by means of hair analysis. The aim of the present study was to clarify if and to what extent it is possible to manipulate the results of hair analyses on tetrahydrocannabinol (THC) by using various commercially available everyday products and products advertised on the internet to be able to reduce the concentrations of drugs in hair. Fifty-four THC-positive hair samples were analyzed using liquid chromatography tandem mass spectrometry; they were analyzed untreated or treated with Vodka Gorbatschow® (n = 19), Seborin® hair tonic (n = 11), Zydot® shampoo (n = 6), Desderman® disinfectant (n = 11) and Head and Shoulders® shampoo (n = 7). A mean reduction of 52% (Zydot® shampoo) to 65% (Desderman®) was shown. Hair treatments could not be detected visually. Hair concentrations could also be decreased to non-detectability by using these everyday hair care products. Therefore, it is recommended to complement abstinence controls using hair samples by urine analysis and to not over-interpret quantitative results of THC concentrations in hair.

Cyclic siloxanes in indoor environments from hair salons in Hanoi, Vietnam: Emission sources, spatial distribution, and implications for human exposure.

In this study, three typical cyclic siloxanes (CSis) were found in hair care products, indoor dust and indoor air samples at hair salons in Hanoi, Vietnam. The total concentrations of CSis in three kinds of hair care products ranged from 8.77 to 515 µg g-1. The mean and median concentrations of CSis in dust samples collected at hair salons were 671 and 654 µg g-1, respectively. The total concentrations of CSis in indoor air samples collected at the hair salons ranged from 415 to 2610 ng m-3 (mean: 1030; median: 849 ng m-3, respectively). Among three cyclic siloxanes mentioned in this study, decamethylcyclopentasiloxane (D5) was found at the highest level in all categories of samples. D5 had also a strong correlation between indoor dust and indoor air from hair salons (the coefficient of determination (R2): 0.852); meanwhile dodecamethylcyclohexasiloxane (D6) and octamethylcyclotetrasiloxane (D4) had good correlations (R2 = 0.618 and 0.585, respectively). This result indicates that hair care products are main emission source of cyclic siloxanes in indoor environments at the hair salons. The average exposure doses to total SCis through both of dust ingestion and inhalation were estimated to be 103 and 79.5 ng kg-bw-1 day-1 for women and men, respectively. These levels were higher than those reported for some Asian countries. This is among the most comprehensive investigations on the emission sources and distributions of cyclic siloxanes in indoor dust and indoor air at hair salons in Vietnam.

A Study on Scalp Hair Health and Hair Care Practices among Malaysian Medical Students.

INTRODUCTION: Scalp care is essential because it determines the health and condition of the hair and prevents the diseases of scalp and hair. The objectives of our study were to correlate race and hair types, to determine the awareness of hair care among Malaysian medical students, and to distinguish the factors that affect the health of hair and scalp. METHODOLOGY: It was a cross-sectional study wherein validated questionnaires were given to 240 medical undergraduate students who belonged to three ethnic races of Malaysia, i.e., Chinese, Malay, and Malaysian Indians after their informed consent. The results were then analyzed using percentage statistics. RESULTS: Chinese students had comparatively healthier scalp without dandruff. Most Chinese and Indians had silky type of hair while Malay had dry, rough hair. Chinese and Indians colored their hair and used various styling methods; while among the Malays, this percentage was very less. Regarding hair care practices, males used only shampoo and females used shampoo and conditioner for hair wash. Students also faced dietary and examination-related stress. CONCLUSION: Results indicate that there exist morphological differences in hair among the studied population. Since most students color their hair and employ various hairstyling methods, they should be educated regarding best hair care practices to improve their scalp hair condition and health.

Evaluation of human exposure to metals from some commonly used hair care products in Nigeria.

The concentrations of nine metals, namely, cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu), cobalt (Co), nickel (Ni), manganese (Mn), zinc (Zn), and iron (Fe), were determined in 26 brands of hair care products including hair relaxers, conditioners and shampoos. The study was aimed at providing information on the possible risks arising from heavy metals associated with the use of these products. The concentrations of the metals were determined by means of atomic absorption spectrophotometry after digestion of the samples with a mixture of acids. The concentrations of the respective metals in hair relaxers, shampoos and conditioners were found to be 0.8-2.5, 0.6-3.0,

Ethnic hair care products may increase false positives in hair drug testing.

The question of why different races appear more susceptible to hair contamination by external drugs remains controversial. This research studied susceptibility of head hair to external cocaine and methamphetamine when hair products have been applied. Three different chemical classes of ethnic hair products were applied to Caucasian, Asian, and African hair. Some products increased the methamphetamine and cocaine concentrations in all hair types. A unique finding of this research is that certain ethnic hair products can replace moisture as a diffusion medium, thereby increasing the susceptibility to contamination over 100-fold compared to petroleum-based products.

Effect of shampoo, conditioner and permanent waving on the molecular structure of human hair.

The hair is a filamentous biomaterial consisting of the cuticle, the cortex and the medulla, all held together by the cell membrane complex. The cortex mostly consists of helical keratin proteins that spiral together to form coiled-coil dimers, intermediate filaments, micro-fibrils and macro-fibrils. We used X-ray diffraction to study hair structure on the molecular level, at length scales between ∼3-90 Å, in hopes of developing a diagnostic method for diseases affecting hair structure allowing for fast and noninvasive screening. However, such an approach can only be successful if common hair treatments do not affect molecular hair structure. We found that a single use of shampoo and conditioner has no effect on packing of keratin molecules, structure of the intermediate filaments or internal lipid composition of the membrane complex. Permanent waving treatments are known to break and reform disulfide linkages in the hair. Single application of a perming product was found to deeply penetrate the hair and reduce the number of keratin coiled-coils and change the structure of the intermediate filaments. Signals related to the coiled-coil structure of the α-keratin molecules at 5 and 9.5 Å were found to be decreased while a signal associated with the organization of the intermediate filaments at 47 Å was significantly elevated in permed hair. Both these observations are related to breaking of the bonds between two coiled-coil keratin dimers.

Análise de formaldeído em produtos capilares: otimização e faixa linear do método analítico empregado no controle da qualidade dos produtos sujeitos à vigilância sanitária

A utilização de formaldeído (FA) como alisante em produtos cosméticos capilares é proibido pela Agência Nacional de Vigilância Sanitária (ANVISA) sendo somente permitido o seu uso como conservante na concentração máxima de 0,2%. Segundo a Associação Brasileira da Indústria de Higiene Pessoal, Perfumaria e Cosmético (ABIHPEC), o Brasil ocupa o segundo lugar em consumo de produtos capilares. O FA foi classificado, em 2006, pela International Agency for Research on Cancer (IARC) no Grupo 1, como carcinógeno em humanos, a partir de suficientes evidências de indução de câncer de nasofaringe em humanos e como causador também de leucemia a partir de 2012. Objetivando o futuro controle da qualidade destes produtos foram determinados os parâmetros para a otimização do método de análise para identificação e quantificação de FA em produtos cosméticos capilares através da técnica de cromatografia líquida de alta eficiência (CLAE). Na CLAE empregou-se coluna de fase reversa de sílica recoberta com octadecilsilano (C18) e como fase móvel a solução de metanol em água 70% (v/v). As condições cromatográficas foram: coluna com 4 mm de diâmetro interno, 250 mm de comprimento e 5 µm de tamanho de partícula, à temperatura ambiente (faixa de 21º à 25º C), fluxo da fase móvel 1 mL/min. e comprimento de onda de 345 nm. O método para análise de FA em produtos capilares através da reação de derivatização com solução 0,1% de 2,4-dinitrofenilhidrazina em ácido clorídrico 0,5 N, empregando o tampão citrato foi otimizado. Foram determinados o pH ideal da reação (4,5) bem como o tempo da reação (2 min.). A faixa de trabalho foi definida de (7,38x10-4) % m/v a (5,17x10-3) % m/v e considerada linear. O produto formado, 2,4-dinitrofenilhidrazona, manteve-se estável até 90 min. quando protegido e quando exposto à luz em 100% e 67%, respectivamente, dos ensaios realizados. Na análise de um produto capilar (máscara) foi detectado FA no qual não se declarava a sua presença. O método mostrou, portanto, ser eficiente na faixa de trabalho estudada na amostra testada.