(a) Schedule III consists of the drugs and other substances, by whatever official name, common or usual name, chemical name or brand name designated, listed in this section.
(b) Stimulants. — Unless specifically excepted or unless listed in another schedule, any material, compound, mixture or preparation which contains any quantity of the following substances having a stimulant effect on the central nervous system, including its salts, isomers (whether optical, position or geometric) and salts of such isomers whenever the existence of the salts, isomers and salts of isomers is possible within the specific chemical designation:
(1) Those compounds, mixtures or preparations in dosage unit form containing any stimulant substances listed in Schedule II which compounds, mixtures or preparations were listed on August 25, 1971, as excepted compounds under 21 C.F.R. §1308.32, and any other drug of the quantitative composition shown in that list for those drugs or which is the same except that it contains a lesser quantity of controlled substances;