Need help with some knowledge of a medication?

When my mother was passing away from cancer, hospice had her on very potent medication. I had not discarded them as of yet. Well, unfortunately a friend (someone I thought was a friend) of mine stole them and replaced with something I'm not familiar with. I use my mobile for the internet and I'm having difficulty accessing any of the sites with a pill identifier. I would appreciate your help! Webmd.Com is usually pretty good. The markings on this pill is DF/7.5 ( one side being DF and the other 7.5 (Thank You So Much In Advance)