title: Effect of potassium present in stratum corneum during non-invasive measurement of potassium in human subjects using reverse iontophoresis.
abstract: OBJECTIVE
  Reverse iontophoresis (RI) is one of the potential techniques used to monitor the concentration of various analytes in body fluids non-invasively. Transdermal extraction of potassium is investigated using RI. In the present work, the effect of potassium on stratum corneum (SC) during RI, feasibility of RI for continuous monitoring of potassium, and use of potassium as internal standard in RI, are investigated.
  
  
  METHODS
  Tape stripping experiment is carried out to find potassium concentration in SC. RI is carried out continuously for 180 min without passive diffusion and after passive diffusion for 60 min. Skin impedance measurements are done at 20 Hz and 20 kHz.
  
  
  RESULTS
  Potassium is found to be in the range 300-650 nmol/cm(2) on SC by tape stripping experiment. Correlation coefficient between blood potassium and extracted potassium through RI after passive diffusion (R(2) = 0.5870) is more than without passive diffusion (R(2) = 0.5117). The skin impedance measurement shows that RI has more effect on SC than superficial layer of SC during RI.
  
  
  CONCLUSIONS
  The present investigations conclude that it is possible to monitor potassium continuously through RI and using potassium as internal standard in RI.
authors.affiliation: Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, India.
authors.forename: E K
authors.initials: EK
authors.lastname: Varadharaj
authors.affiliation: Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, India.
authors.forename: N
authors.initials: N
authors.lastname: Jampana
mesh_terms: D000328:Adult; D001458:Bandages; D001826:Body Fluids / Q000737:chemistry*; D004817:Epidermis / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007478:Iontophoresis / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D011188:Potassium
keywords: internal standard; interstitial fluid; natural moisturizing factor; reverse iontophoresis; transdermal potassium extraction