The U.S. has vast reserves of natural gas that are commercially viable as a result of advances in horizontal drilling and hydraulic fracturing technologies enabling greater access to gas in shale formations.
Yes, you can open the Keflex capsule and take the contents. However, that way you may miss some of the dose if all the contents of what you mixed it in don't get eaten. And the taste of the antibiotic powder may not be so nice.
i don't see why you would, cephalexin (or Keflex) is an antibiotic. It isn't a pain reliever. If there was an infection that is causing the toothache then taking Keflex may eventually diminish the pain by eliminating the swelling from the infection. But that is at the discretion of your medical provider.