Thecompositionofcosmeticsisverycomplexandvarieswith differenttypes.Mostcosmeticsareprocessedfromthecosmetic matrix(base)plussomeothernecessaryingredients(additives). Cosmeticsubstratesarethebasicrawmaterialsofcosmetics.They aremainlyoilyrawmaterials,includingoils,waxes,hydrocarbons, andhigherfattyacidsandhigheralcoholsthatmakeupthese ingredients.
Salicylicacid
Alsoknownasβ-hydroxyacid(BHA,betahydroxyacid),salicylic acidhasmultiplefunctionsandcansolvevariousproblemsthatcause acne.Dermatologistshaveusedsalicylicacidtoexfoliateskinfor decades,butit'salsoananti-irritantingredient.Salicylicacidis similarinstructuretoaspirin(theyarebothsalicylates,andaspirinis alsonamedacetylsalicylicacid),soitalsohasanti-inflammatory properties.Salicylicacidisalsoantiseptic,whichisabigreasontouse ittotreatacne.Inaddition,studieshavefoundthatitcanincrease skinthickness,improveskinbarrierfunction,andpromotecollagen synthesis.Inaddition,salicylicacidataconcentrationof8%to12% isaneffectiveexfoliatingtreatment,andsalicylicacidata concentrationof0.5%to2%ismilderinnature,similartoAHAs.In addition,salicylicacidcanpenetratedeepintothepores(AHAscannot) andremovetheagingkeratinocytesonthesurfaceoftheskinandin thepores,soitcanbeusedtoeffectivelyfightacne.
AHA
Alsonamedalphahydroxyacid,AHAscanbeextractedfromvarious plantsormilk,but99%ofAHAsincosmeticsaresynthetic.AHAsin lowconcentrations(lessthan3%)canactaswaterretainers.AHAs haveanexfoliatingeffectwhentheconcentrationisabove4%andthe pHisbetween3and4.ThemosteffectiveandmostresearchedAHAs areglycolicandlacticacids.Malicacid,citricacid,andtartaricacidare alsoeffective,buttheyarecomparativelylessstableandnotsuitable foruseontheskin;andtherearefewstudiestoprovethattheyare beneficialtotheskin.AHAscanirritatethemucousmembranesand causeinflammation.AfterusingAHAs,thelivingepidermalcellsinthe epidermisandtheglucosaminoglycaninthedermiswillincrease. Numerousstudiesreporttheanti-agingbenefitsofusingAHAs (includingglycolicacidandlacticacid)ontheskin.AHAscanremove sun-damagedkeratinocytesonthesurfaceoftheskin,butthislayer ofkeratinocyteshasacertainsunprotectioneffect,sotheskinis morelikelytobesunburnedafterusingAHAs.However,thisproblem
doesnotoccurwithsunscreenproducts.
Retinol
Iftheweakeningofthedeepskinconnectivetissueofthethighsisthe maincauseofcellulite(andtheexcessaccumulationoffat),then improvingthestructureoftheskinconnectivetissuewillnaturally improvecellulite,andnowmoreandmoreresearchsupportsthisidea. Retinolisoneofthesubstancesknowntoimproveskinstructure.Of alltheanti-celluliteproducts,thosefortifiedwithretinolshouldbethe firstchoice.However,mostrelatedproductscontainverylittleretinol, andretinoliseasilydecomposedintheair,butthepackagingofmost productscannotensurethestabilityofretinol.
Avobenzone
Avobenzoneisasyntheticsunscreeningredient(fullnameButyl Methoxydibenzoylmethane),whichcanprotectagainst full-wavelengthUVArays.
Titaniumdioxide
Titaniumdioxideisaninertmineralusedincosmeticsasathickener, whitener,lubricant,andsunscreen.ItprotectstheskinfromUVAand UVBraysandisnon-irritatingtotheskin.