Thanks for the notice.
As a reminder, here's the gallery of photos from the movie when it was at a mexican film festival years ago : http://www.ararchive.com/gallery3/album19/Movie-La-Formula-del-Doctor-Funes?page=1
The movie include the AR of Doctor Funes, an old scientist who become twelve again. When sent to school later on, he regress the seemingly autoritarian female teacher into a little girl by giving her a spiked apple. She's thus forced to go to school as one of the students.
Then he regress a cop and his dog into a little baby and puppy, then some old lady, and a whole bunch of old people at a pension House.
There's also the rival scientist drinking what is apparently a intentionaly spiked version of the potion, transforming him into a tiny donkey.
Would be great being able to see all of this.