Percocet used for pain relief is a narcotic medication and prescriptions can prevent people from getting high on Percocet without medical reason.In fact, the Percocet high feeling can get you into lots of problems.
I think the formula of the perfume itself decides how fast it will spoil. My perfumes from Britney Spears Curious and Salvatore Ferragamo went bad within a year and a half. The Britney Spears one developed some precipitation and started smelling like alcohol, while the Salvatore Ferragamo just smelled plain weird.
One of our first year labs helps you understand why perfumes smell the way they do. In fact you start doing some chemistry yourself as soon as your eyes open - your sense of vision works because a small organic molecule changes shape in the back of your eye when light hits it. Chemistry is truly the central science.