title: Use of an intraluminal guide wire in linear microdialysis probes: effect on recovery?
abstract: OBJECTIVE
  For microdialysis studies in the skin, laboratory-made linear probes are often used. Probes can be assembled with or without a stainless-steel guide wire in the lumen of the dialysis fibre. From a theoretical viewpoint, this will alter the performance of the probe. The aim of this study was to compare the in vitro microdialysis recovery using probes with and without an internal guide wire, employing two different model drugs and a range of perfusate flow rates.
  
  
  METHODS
  In vitro microdialysis recovery experiments were performed with and without internal guide wires at perfusion flow rates from 1 to 15 microL/min, using either salicylic acid or metronidazole as test compounds at 5 mg/L. Phosphate buffer (pH 7.4) was used as perfusate. Dialysates were analysed by a validated HPLC assay with spectrophotometric detection.
  
  
  RESULTS
  For both test compounds, the mean microdialysis recovery did not differ significantly between microdialysis probes with and without an internal guide wire at lower flow rates. At very high flow rates (10-15 microL/min), a significant difference in recovery could be seen for probes with internal guide wires when compared with probes without.
  
  
  CONCLUSIONS
  The use of a stabilizing internal guide wire in linear microdialysis probes did not influence the in vitro recovery of microdialysis at volumetric flow rates below 10 microL/min. These are the flow rates most frequently used for in vivo microdialysis studies in the skin.
authors.affiliation: Dermatopharmacotherapy Division, Department of Dermatology, Pomeranian Medical University, 72 Powstancow Wlkp. Str., PL-70-111 Szczecin, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Klimowicz
authors.forename: Stanislawa
authors.initials: S
authors.lastname: Bielecka-Grzela
authors.forename: Lotte
authors.initials: L
authors.lastname: Groth
authors.forename: Eva
authors.initials: E
authors.lastname: Benfeldt
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods*; D008795:Metronidazole / Q000032:analysis; D017551:Microdialysis / Q000295:instrumentation* / Q000379:methods*; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D020156:Salicylic Acid / Q000032:analysis; D012680:Sensitivity and Specificity; D014159:Transducers
chemical_list: D008795:Metronidazole; D020156:Salicylic Acid