title: Hard water softening effect of a baby cleanser.
abstract: BACKGROUND
  Hard water is associated with atopic dermatitis (eczema). We wanted to determine if a baby cleanser and its individual components altered free ionized calcium (Ca2+) in a simulated hard water baby bath. For these studies, an in vitro determination of free Ca2+in a simulated hard water baby bath, and an in vivo exploratory study of free Ca2+absorption into skin from hard water were performed.
  
  
  METHODS
  Free Ca2+was measured with an ion-sensitive electrode in vitro in hard water (100-500 ppm, Ca2+) before and after addition of the cleanser and/or its components. In an exploratory study, absorption of Ca2+into skin from hard water was determined in three female participants (aged 21-29 years).
  
  
  RESULTS
  At an in-use dilution of 1%, the test cleanser reduced free Ca2+from ~500 ppm to <200 ppm; a 10% in-use dilution bound virtually all free Ca2+. The anionic surfactant component contributed the most to this effect. In the exploratory in vivo study, we measured a reduction of ~15% in free Ca2+from simulated hard water over 10 minutes.
  
  
  CONCLUSIONS
  Baby cleansers can bind free Ca2+and reduce the effective water hardness of bath water. Reducing the amount of free Ca2+in the water will reduce the availability of the ion for binding to the skin. Altering or reducing free Ca2+concentrations in bath water may be an important parameter in creating the ideal baby bath.
authors: Skin Care Research & Development, Johnson & Johnson Consumer Inc., Skillman, NJ, USA.
authors: Russel M
authors: RM
authors: Walters
authors: Skin Care Research & Development, Johnson & Johnson Consumer Inc., Skillman, NJ, USA.
authors: Emmanuel
authors: E
authors: Anim-Danso
authors: Skin Care Research & Development, Johnson & Johnson Consumer Inc., Skillman, NJ, USA.
authors: Stephanie M
authors: SM
authors: Amato
authors: Skin Care Research & Development, Johnson & Johnson Consumer Inc., Skillman, NJ, USA.
authors: Kimberly A
authors: KA
authors: Capone
authors: Skin Care Research & Development, Johnson & Johnson Consumer Inc., Skillman, NJ, USA.
authors: M Catherine
authors: MC
authors: Mack
authors: Skin Care Research & Development, Johnson & Johnson Consumer Inc., Skillman, NJ, USA.
authors: Lorena S
authors: LS
authors: Telofski
authors: Skin Care Research & Development, Johnson & Johnson Consumer Inc., Skillman, NJ, USA.
authors: David A
authors: DA
authors: Mays
keywords: bath; cleanser; hard water; infant; neonate; surfactant