A novel administration route of edaravone--II: mucosal absorption of edaravone from edaravone/hydroxypropyl-beta-cyclodextrin complex solution including L-cysteine and sodium hydrogen sulfite.

We examined the pharmacokinetics of edaravone when edaravone/hydroxypropyl-beta-cyclodextrin (HPbetaCD) complex solution, including L-cysteine (L-Cys) and sodium hydrogen sulfite (SHS), was administered intravenously, rectally and via the oral mucosa. In oral mucosal administration, atomized edaravone/HPbetaCD complex solution that contained L-Cys and SHS was sprayed into the mouth of Wistar rats. Oral mucosal and rectal administration of edaravone/HPbetaCD complex solution that contained L-Cys and SHS was compared with that for edaravone/HPbetaCD complex solution without L-Cys and SHS. When edaravone 0.25-1.0 mg was administered intravenously, C(0) and AUC(0-60) were linear. In oral mucosal and rectal administration, C(max) and AUC(0-60) of edaravone/HPbetaCD with L-Cys and SHS were significantly higher than those of edaravone/HPbetaCD without L-Cys and SHS. On the other hand, bioavailability of oral mucosal, rectal and oral administration was about 100, 63.5 and 26.6%, respectively. This study suggested that L-Cys and SHS were useful for the oral mucosal and rectal administration of edaravone.