The influence of HMW cosmeticingredientson theskin parameters Katarzyna Pytkowska MD Eng. Maria Statkiewicz BSc. Jacek ArctPhD. Eng. Academy of Cosmetics and Health Care, Warsaw, Poland
Hyaluronicacid and chitosan • Hyaluronicacid and chitosanarethe most popular cosmetichydrophilicHMW ingredients of moisturizing and film-forming activity. • Hygroscopicity • Chelatingproperties • Hyaluronicacidiswidelyusedinpharmacetical industry (in wounddressingsamongothers) and aestheticmedicine (filler). • Hyaluronicacidhydrolysis/degradation products possessbiologicalactivity • Chitosanisalsousedinwoundhealing, intextile industry, as chelating agent etc.
Materials and methods • We investigated the influence of low concentrations of chitosanglycolate (CG) and hyaluronic acid (HA) after topical applicationfrom: • Hydrogelscontaining 0,2-0,6 % w/w of thepolymer • Oil-in-wateremulsionscontaining 0,2-0,6 % w/w of thepolymer • on the: • Skin barrierproperties (TEWL measurementin controlled temperature and humidity conditions) • Skin hydration (corneometricmeasurementincontrolled temperature and humidity conditions) • Basic skin sensory parameters
Materials and methods • Sensory evaluation was performed on the group of 10 trained panelists with dry or normal skin in controlled temperature and humidity conditions. • The evaluation consisted of the assessment of • the general and visual criteria (consistency, adhesion), • feelings during the application (spreadability) • afterfeel (tackiness, skin smoothness) • Thefive-point sensory scale was applied (from 1 - “the worst” to 5 - “the best”).
untreated skin untreated skin placebo hydrogels placebo hydrogels HA hydrogel HA hydrogel CG hydrogel CG hydrogel
untreated skin placebo hydrogels HA hydrogel CG hydrogel
untreated skin untreated skin Placebo emulsions placebo emulsions HA o/w emulsion HA o/w emulsion CG o/w emulsion CG o/w emulsion
untreated skin placebo emulsions HA o/w emulsion CG o/w emulsion
Skin barrier assessment • Investigated HMW polymersstronger influence TEWL reduction by hydrogelsthan by emulsions, • In morecomplex systems thepolymer influence could be masked by otheringredients (emollients?) • In hydrogels: thehigherconcentration of polymer , thestronger TEWL reduction, • But: we investigated TEWL on the group of panelists of damaged/impairepidermalbarrier (↑TEWL), investigations on the group of normalbarrierpropertiesshould be conductedinthefuture.
Corneometricevaluation placebo hydrogels CG and HA hydrogels Dn
Corneometric evaluation results • Strong film-forming properties of CG and HA causecorneometrycompletelyuselessmethod for skin hydrationevaluation of hydrogels and oil-in-wateremulsionscontaining ≥0,2% of thepolymer • As TEWL is not goodindicator of hydration, the sensory subjectiveassessmentremains a way for thatkind of evaluation
Sensory evaluation • Becausehydrogelswereperceived by panelistsduring TEWL and hydrationassessmentas „too film-forming” and „unpleasant”, we havecheckedonly sensory parameters of polymer-containingemulsions.
Sensory evaluation results for o/w emulsions containing from 0,2 to 0,6% of hyaluronic acid
Sensory evaluation results for o/w emulsions containing from 0,2 to 0,6% of chitosan
Sensory evaluationresults • For CG-containing emulsions a dependence of polymer concentration on received scoring is strong, • Preparation of 0.6 % CG concentration is standing out high tackiness, so this parameter was assessed to the only 1 point • Emulsions containing hyaluronic acid are less sensory-dependent on thepolymerconcentration. • Only high concentration of the HA influences on the tackiness of cosmetic. • HA-containingemulsionswerebetteracceptedthanCG-containingemulsions. • As sensory parametersarestronglyformulation-dependent, resultsof ourexperiments cannot be treated as the general rule withoutfurtherresearch