Absorption of dexamethasone sodium phosphate in human connective tissue using iontophoresis.
BACKGROUND
Iontophoresis ostensibly facilitates the delivery of medications through the skin to underlying tissues using a direct electrical current. Dexamethasone is the most commonly used medication with iontophoresis to treat a variety of connective tissue disorders.


OBJECTIVE
Iontophoresis will facilitate the absorption of dexamethasone into connective tissue compared with diffusion.


METHODS
Controlled laboratory study.


METHODS
Twenty-nine adults undergoing anterior cruciate ligament reconstructive surgery using the semitendinosus/gracilis autograft were randomly assigned to either a true iontophoresis (TI) or sham iontophoresis (SI). In the TI group, a 40-mA/min dose of iontophoresis using a 0.4% (4 mg/mL) solution of dexamethasone was used targeting the semitendinosus tendon just before surgery. The SI group underwent the same treatment, but the machine was not turned on. Tissue was extracted within 4 hours of treatment and analyzed for dexamethasone. In addition, 2 control samples were sent to the laboratory for analysis.


RESULTS
There was a statistically significant difference in dexamethasone concentrations between the groups (P = .0216). Of the 16 samples in the TI group, 8 had measurable amounts of dexamethasone, with an average concentration of 2.906 ng/g of tendon tissue. In the SI group, 1 of the 13 samples had measurable amounts of dexamethasone with an average concentration of 0.205 ng/g of tendon tissue. The control samples contained no dexamethasone.


CONCLUSIONS
Iontophoresis facilitates the transmission of dexamethasone to connective tissues in humans.


CONCLUSIONS
Iontophoresis can deliver dexamethasone to connective tissues in humans.
Gurney
A Burke
AB
University of New Mexico School of Medicine, Department of Orthopaedics and Rehabilitation, Albuquerque, New Mexico, USA. bgurney@salud.unm.edu
Wascher
Daniel C
DC
D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage* / Q000378:metabolism; D003238:Connective Tissue / Q000502:physiology*; D003907:Dexamethasone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism; D006801:Humans; D007478:Iontophoresis / Q000295:instrumentation; D009516:New Mexico; D012869:Skin Absorption; D013710:Tendons / Q000637:transplantation
D000893:Anti-Inflammatory Agents; C004180:dexamethasone 21-phosphate; D003907:Dexamethasone