title: Preparation and evaluation of cosmetic patches containing lactic and glycolic acids.
abstract: BACKGROUND
  Alpha-hydroxy acids such as glycolic acid (GA) and lactic acid (LA), are used in cosmetic patches. The important fact in cosmetic patches is its suitable adhesion and peel properties.
  
  
  OBJECTIVE
  The objective of this study was to prepare LA- and GA-containing cosmetic patches and evaluate in-vitro/in-vivo correlation of adhesion properties.
  
  
  METHODS
  Pressure-sensitive adhesives with different concentrations of GA and LA were cast on a polyethylene terephthalate film. The patches were evaluated for peel adhesive strength. On the basis of in vitro adhesion properties the patches were selected for wear performance tests and skin irritation potential.
  
  
  RESULTS
  The adhesion properties (adhesion to steel plate and skin) and cohesive strength tests indicated the substantial influence of GA and LA concentrations. Based on in vitro adhesion studies the patches containing 3% (w/w) GA were selected for in vivo studies. In vivo studies show that a formulation containing 3% GA displays good adhesion on the skin, but it leaves little residues on the skin. Skin Irritation studies on healthy human volunteers showed negligible erythema at the site of application after 48 h.
  
  
  CONCLUSIONS
  The noninvasive patch test model was found useful for detecting irritant skin reactions to the cosmetic patch containing GA. Our results demonstrated a strong correlation between the adhesion to steel plate and adhesion to skin. But a weak correlation between the degree of adhesive residue on the skin in in vitro and in vivo tests was observed for the formulation containing 3% (w/w) GA.
authors.affiliation: Department of Novel Drug Delivery Systems, Science Faculty, Iran Polymer and Petrochemical Institute, Tehran, Iran. H.Mahdavi@ippi.ac.ir
authors.forename: H
authors.initials: H
authors.lastname: Mahdavi
authors.forename: Z
authors.initials: Z
authors.lastname: Kermani
authors.forename: G
authors.initials: G
authors.lastname: Faghihi
authors.forename: A
authors.initials: A
authors.lastname: Asilian
authors.forename: H
authors.initials: H
authors.lastname: Hamishehkar
authors.forename: A
authors.initials: A
authors.lastname: Jamshidi
mesh_terms: D000268:Adhesiveness; D000279:Administration, Cutaneous; D003357:Cosmetic Techniques; D016503:Drug Delivery Systems / Q000009:adverse effects; D004890:Erythema / Q000209:etiology; D006016:Glycolates / Q000008:administration & dosage*; D006801:Humans; D019344:Lactic Acid / Q000008:administration & dosage*; D008422:Materials Testing; D009994:Osmolar Concentration; D013997:Time Factors
chemical_list: D006016:Glycolates; C031149:glycolic acid; D019344:Lactic Acid