Abstract
Objective
We prepared the transdermal ketamine patch, determined the size of the patch to yield proper plasma ketamine level due to human skin permeability and the amount of residual ketamine in the patch, and estimated the utility of this ketamine transdermal patch when it will be applied to patients.
Methods
A ketamine patch was prepared with ketamine hydrochloride intramuscular solution (3.0mg/cm2). The ketamine patch was put on the skin samples taken from the human. The solutions of the diffusion cell were examined every two hours after the application until 30 hours. The amount of ketamine that has penetrated into the skin was measured by using HPLC system, and Flux of transdermal ketamine patch was defined.
Results
The cumulative ketamine permeation amount was found to be 785.6 mg/cm2 at the 30-hour sampling, showing a stable Flux of 30.1 mg/cm2/hr during the period from 10 to 30 hours of sampling.
Conclusion
We have been attempting to formulate transdermal ketamine patches at a size of 155 cm2 to yield a plasma ketamine level of 50 ng/mL for use in the clinical practice setting. The patch may become a formulation of choice as an analgesic adjuvant for combined use with opioids.