Do urea/ammonium lactate combinations achieve better skin protection and hydration than either component alone?
Twenty subjects with healthy skin were treated with the following formulations for two weeks: drug-free W/O vehicle, 5% ammonium lactate (CAS 52003-58-4) in W/O vehicle, 5% urea (CAS 57-13-6) in W/O vehicle, 3% ammonium lactate + 3% urea in W/O vehicle, 5% ammonium lactate + 5% urea in W/O vehicle. These formulations were applied in randomized order to 6 test areas on the forearms; one area was left untreated. Repetitive washings were additionally performed in the second treatment week. TEWL, stratum corneum water content (corneometry-determined electrical capacitance), and cutaneous blood flow (laser Doppler) were measured at baseline, day 7, and day 14. 5% urea and both ammonium lactate/urea combinations produced significant stratum corneum hydration and improved stratum corneum barrier function; there were no significant differences between these three treatments.
Gloor
M
M
Department of Dermatology, Klinikum der Stadt Karlsruhe, Germany. max@prof-gloor.de
Fluhr
J
J
Lehmann
L
L
Gehring
W
W
Thieroff-Ekerdt
R
R
D000328:Adult; D002626:Chemistry, Pharmaceutical; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology* / Q000627:therapeutic use; D012867:Skin / Q000098:blood supply / Q000187:drug effects*; D018709:Statistics, Nonparametric; D014508:Urea / Q000494:pharmacology* / Q000627:therapeutic use
D004338:Drug Combinations; D000644:Quaternary Ammonium Compounds; D019344:Lactic Acid; D014508:Urea