Ritalin LA 10, 20, 30, and 40 mg capsules provide in a single dose the same amount of methylphenidate as dosages of 5, 10, 15, or 20 mg of Ritalin® tablets given b.i.d. The active substance in Ritalin LA is methyl α-phenyl-2-piperidineacetate hydrochloride, and its structural formula is....