title: Assessment of topical bioequivalence using dermal microdialysis and tape stripping methods.
abstract: OBJECTIVE
  To assess the bioequivalence of two commercial topical formulations of oxytetracycline HCl by tape stripping and microdialysis in healthy volunteers.
  
  
  METHODS
  Tape stripping study was conducted on 12 healthy volunteers. After a 30-minute application of the formulations, adhesive tapes were used to sample stratum corneum at 0.25, 0.5, 1, 1.5, 2, 3, 4 hr. Ten of these volunteers were included in the microdialysis study with a period of 4 weeks between the experiments. Microdialysis probes were inserted into the dermis of the forearm. Following the application of the test and reference simultaneously, dialysates were collected in 30-minute sampling intervals up to 4 hr.
  
  
  RESULTS
  Pharmacokinetic evaluation by microdialysis yielded that the test could not be said to be bioequivalent to the reference at 90% CI. The intersubject variability of oxytetracycline content in stratum corneum was moderate when it was compared to the dermal levels. The test was found to be bioequivalent to reference according to the dermatopharmacokinetic evaluation by tape stripping.
  
  
  CONCLUSIONS
  No significant correlations were found between microdialysis and tape stripping methods as regarding the topical bioequivalence of oxytetracycline HCl formulations.
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, Gazi University, Etiler, 06330 Ankara, Turkey.
authors.forename: Tuba
authors.initials: T
authors.lastname: Incecayir
authors.forename: Ilbeyi
authors.initials: I
authors.lastname: Agabeyoglu
authors.forename: Ulver
authors.initials: U
authors.lastname: Derici
authors.forename: Sukru
authors.initials: S
authors.lastname: Sindel
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008297:Male; D017551:Microdialysis; D010118:Oxytetracycline / Q000008:administration & dosage / Q000493:pharmacokinetics*; D012867:Skin / Q000000981:diagnostic imaging / Q000378:metabolism*; D012869:Skin Absorption; D053832:Surgical Tape; D053719:Tandem Mass Spectrometry; D013810:Therapeutic Equivalency; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D010118:Oxytetracycline