http://www.pharmcast.com/Patents/040400OG/6046187_anesthesia040400.htm

This patent application is a bit heavy in places but the idea is to reactivate a local anesthetic site with a slow releasing glucocorticosteroid.

Since we are not going to find anything designed for our kids maybe a lateral application is possible. The patent application is quite old(1996) so a fair amount of work should have already been done on this technology.  They were looking at polymers to produce the slow release effect. Read it and see if you think there is anything here.

ShaunP.