it depends. formulations are destroyed by heat via 2 mechanisms: 1) breakdown 2) reaction with other things in the formulation
breakdown is primarily influenced by heat. the higher the heat, the more it breaks down. if you get it hot enough the molecule can denature, bond with itself, all that sort of thing. when you cook things in an oven, the heat is not evenly distributed. the back of the oven is a lot hotter than the front. also, the container your gear was in may absorb radiating heat, making it much, much hotter than 250. this happens a lot with glass, which is why you usually use a water bath or something like that.
reaction with other stuff depends on temperature as well as other things in the reaction vessel. what oil was in it? any contaminants? any water? steam? salt? preservative?
no one here can tell you if you killed your product because no one knows what was in it in the first place. furthermore i personally dont know how fast your drug will react/decompose (im not about to hunt down this data for you, it is a bitch to find and youll usually only get it from the manufacturer) and i cant even guess what sort of heat spikes you got in your oven/glassware
for all i know the smoothness may be there because you burned away a volatile agent originally in the formulation which was there for a purpose, eg a preservative. or you might have fluked it and killed an organism, if one was present. who knows.
cheers