Bear spray is typically at least 5% OC and I've seen 10%. It's the same thing that's used on humans other than size of the bottle and sometimes OC concentration.

It may or may not work on canids. Some dogs seem to be unaffected by OC, so it's possible that a coyote may not be deterred.

The one time I had a coyote stalking me, it so happened that I was walking to the rifle range. When I unslung the rifle the coyote vanished. I figure it had seen a rifle before and wanted urgently to not see one again.