Gringo, there are products that will allow you to mount into drywall:

http://www.itwbuildex.com/ezprod.htm

I wouldn't necessarily use them to mount 50lbs, but the VP150 is less than 25lbs so you should be OK. I've mounted items using them, but I don't think they were more than 25lbs.

To be REALLY safe, though, you might want to use something stronger like the ones listed in the bottom half of this page:

http://www.naturalhandyman.com/iip/inffastener/infanchor/infanchor.html