title: Adapalene gel 0.1% is better tolerated than tretinoin gel 0.025% among healthy volunteers of various ethnic origins.
abstract: BACKGROUND
  The efficacious acne treatment adapalene gel 0.1% is significantly less irritating than tretinoin of various concentrations and formulations, according to several clinical studies conducted predominantly in Caucasian patients.
  
  
  OBJECTIVE
  To confirm the lower irritation potential of adapalene gel 0.1% compared to tretinoin gel 0.025% among volunteers of various ethnic origins and to explore the difference in the irritant susceptibility among ethnic groups.
  
  
  METHODS
  The study was a single-centre, randomized, investigator-masked and intra-individual comparison. Healthy volunteers applied adapalene and tretinoin daily to the face for 21 days and to the forearms for 4 days, and were then evaluated for the level of irritation.
  
  
  RESULTS
  The irritation potential of adapalene gel 0.1% was significantly lower than that of tretinoin gel 0.025% in all tolerability assessments, irrespective of the volunteers' ethnic origins. The between-treatment differences were similar among various ethnic groups. Statistically significant but small inter-ethnicity differences were observed in the evaluation of facial signs, with Caucasians being less susceptible than Chinese, Asian Indians and Malays.
  
  
  CONCLUSIONS
  Adapalene gel 0.1% was significantly better tolerated than tretinoin gel 0.025% among various ethnic groups. The patients' ethnic origins had no impact on the difference between adapalene and tretinoin treatments in terms of tolerability.
authors.affiliation: National Skin Centre, Singapore. clgoh@nsc.gov.sg
authors.forename: Chee Leok
authors.initials: CL
authors.lastname: Goh
authors.forename: Mark B Y
authors.initials: MB
authors.lastname: Tang
authors.forename: Philippe
authors.initials: P
authors.lastname: Briantais
authors.forename: Alexandre
authors.initials: A
authors.lastname: Kaoukhov
authors.forename: Pascale
authors.initials: P
authors.lastname: Soto
mesh_terms: D000068816:Adapalene; D000279:Administration, Cutaneous; D000293:Adolescent; D000328:Adult; D000368:Aged; D003879:Dermatologic Agents / Q000008:administration & dosage / Q000009:adverse effects*; D005782:Gels; D006801:Humans; D008875:Middle Aged; D009281:Naphthalenes / Q000008:administration & dosage / Q000009:adverse effects*; D016037:Single-Blind Method; D012871:Skin Diseases / Q000139:chemically induced* / Q000208:ethnology* / Q000473:pathology; D023422:Skin Irritancy Tests; D014212:Tretinoin / Q000008:administration & dosage / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D003879:Dermatologic Agents; D005782:Gels; D009281:Naphthalenes; D000068816:Adapalene; D014212:Tretinoin