Study On Transdermal Absorption And Toxicity Of P-phenylenediamine In Hair Dyes

Background: In recent years,with the increase in disposable income and living standard,an increasing number of people have joined the wave of dyeing hair.Whether young or middle-aged,the pursuit of black hair has never stopped.Hair dyes not only make people beautiful,but also affect people's health.This may cause a series of allergic diseases such as allergic contact dermatitis due to hair dyeing.The problems caused by hair dyes have been widely concerned and valued by researchers from all over the world.Recently,research methods and directions for hair dyes have been more extensive.According to our national conditions and Asian physique,most of the hair dyes used in China are black hair dyes,and their components are mainly pphenylenediamine(PPD).Other colors hair dyes are very popular among young people,and their ingredients are basically combined with derivatives of p-phenylenediamine and other substances.In human and animal experiments,p-phenylenediamine exhibits sensitization.The molecular characteristics of PPD mean that it penetrates the skin easily,so more and more researchers are working on the percutaneous absorption of PPD in hair dyes and damage to the skin.The troubles of hair dyes make us explore the mechanisms,and may help to reduce the damage of hair dyes to the body and improve the hair dye ingredients in a certain direction.To explore whether p-phenylenediamine have a serious impact on our health,and what is the percutaneous absorption rate and amount,which is an important aspect in the field of hair dye research.Objective: According to the pathological section method,explore the depth and speed of transdermal absorption of PPD in hair dye,and understand the damage of PPD to skin tissue.The study of transdermal absorption of hair dye provides a method from another angle.The method provides a theoretical and experimental basis for reducing damage such as contact dermatitis caused by hair dye.Methods: We use the same brand and the same type of hair dye,which was uniformly applied to the back of guinea pigs and mice,and divided into control group,30 minute group,1 hour group,2 hour group and 3 hour group according to different dyeing time.After reaching the corresponding time,the mice and guinea pigs were killed and the tissue was taken into hematoxylin-eosin(HE)stained sections and frozen sections.The histopathological sections of the skin were observed and analyzed.Results: HE staining experimental group: Compared with the control group,tissue edema was aggravated over time,inflammatory cells increased,and lymphocytosis was the main cause,and the structure of suspected phagocytic cells was observed.Frozen section experimental group: Compared with the control group,with the increase of time,the color of the hair follicles was darken,black particulate matter was visible in the tissue,the color of the tissue was gradually darken,and the penetration depth of PPD in the hair dye was deepened and peaked at 3 hours.Conclusions: The frozen section method can indicate the transdermal absorption depth and speed of p-phenylenediamine in the hair dye.The accumulation of pphenylenediamine in the skin tissue become the largest at 3 hours.The damage of pphenylenediamine to the tissue gradually increases over time.