There are commercial adhesive removers that can take off the gum from price tags and tape residue from plastic items. What many people don't know is that there is an alternative that is probably in your kitchen right now.
Take a few drops of any edible cooking oil and put it on the spot you wish to remove the adhesive from. Gently rub it into the adhesive, and it will dissolve the residue. Wash off the oil with soap and water, and then dry.