Oral
dosage forms and traditional transdermal patches are inadequate for complex
clonidine therapy dosing schemes, because of the variable dose/flux requirement for the treatment of
opioid withdrawal symptoms. The purpose of this study was to evaluate the in vitro transdermal flux changes of
clonidine in response to alterations in
carbon nanotube (CNT) delivery rates by applying various electrical bias. Additional skin diffusion studies were carried out to demonstrate the therapeutic feasibility of the system. This study demonstrated that application of a small electrical bias (-600 mV) to the CNT membrane on the skin resulted in a 4.7-fold increase in
clonidine flux as compared with no bias (0 mV) application. The high and low
clonidine flux values were very close to the desired variable flux of
clonidine for the treatment of
opioid withdrawal symptoms. Therapeutic feasibility studies demonstrated that CNT membrane served as the rate-limiting step to
clonidine diffusion and lag and transition times were suitable for the
clonidine therapy. Skin elimination studies revealed that
clonidine depletion from the skin would not negatively affect
clonidine therapy. Overall, this study showed that
clonidine administration difficulties associated with the treatment of
opiate withdrawal symptoms can be reduced with the programmable CNT membrane transdermal system.