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.
Some industry experts say that perfume should be replaced every year, but properly stored, perfumes should last much longer. Most perfumes will keep several years, some will keep many more years than that. To store perfume properly, keep it away from heat and light. A dark closet or a covered box is best.