Dermal, subdermal, and systemic concentrations of granisetron by iontophoretic delivery.
OBJECTIVE
The purpose of this work was to demonstrate the iontophoretic delivery of granisetron hydrochloride by novel, self-contained iontophoretic patches and to determine the subcutaneous and dermal absorption kinetics using microdialysis.


METHODS
In vitro iontophoretic delivery of granisetron hydrochloride was evaluated at 5, 10, or 20 mg/ml concentrations of donor using Franz diffusion cells and hairless rat skin as a membrane. In vivo studies were performed in hairless rats. Animals received either subcutaneous or dermal microdialysis probes and iontophoretic patches filled with drug formulation were applied on the abdominal area such that the probe lies below the anode chamber. Blood and microdialysate samples were collected at different time intervals. Intravenous administration of granisetron was also done to determine the basic pharmacokinetic parameters.


RESULTS
Iontophoretic patches delivered current constantly throughout the patch application. The patches delivered granisetron hydrochloride at a rate of 14.91+/-4.53 microg/min/kg. Similar concentrations of granisetron hydrochloride in dermal and subcutaneous tissue were observed. Depot formation was identified in the subcutaneous and dermal profiles, indicating that subcutaneous structures are also responsible for the depot formation of the drug in the dermis.


CONCLUSIONS
The patches successfully delivered granisetron hydrochloride by iontophoresis and depot formation was observed in the dermal and subcutaneous structures in the skin.
Chaturvedula
Ayyappa
A
Department of Pharmaceutical Sciences, Mercer University, Atlanta, Georgia 30341, USA.
Joshi
Dipty P
DP
Anderson
Carter
C
Morris
Russ
R
Sembrowich
Walter L
WL
Banga
Ajay K
AK
D000465:Algorithms; D000818:Animals; D000932:Antiemetics / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D017829:Granisetron / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D007275:Injections, Intravenous; D007478:Iontophoresis; D008297:Male; D051379:Mice; D017551:Microdialysis; D015233:Models, Statistical; D012869:Skin Absorption; D013050:Spectrometry, Fluorescence; D014018:Tissue Distribution
D000932:Antiemetics; D017829:Granisetron