Another factor that makes inventory different from other assets is that its usefulness can actually diminish over time. Cash, for instance, maintains its usefulness to you over time.
Lethal injection is done by using three chemicals. The chemicals are usually sodium thiopental (an anesthetic), pancuronium bromide (used to paralyze the person being injected), and potassium chloride (to stop the heart so that the person being injected dies).
One important success factor is the dosage-how much of any particular drug needs to be taken for it to be lethal. Minimum lethal doses (MLDs) were historically calculated based on animal testing, with the results extrapolated for humans.