The set of chemical substances that could be synthesized 100 years ago is a tiny fraction of the size of the set of chemical substances that can be synthesized now. A 100 year old cola recipe almost certainly contains only naturally occurring compounds, while a brand new pharmaceutical is almost guaranteed to contain synthetic compounds.
Additionally, creating a substitute cola recipe only requires mimicking the taste and physical characteristics. When reverse engineering a pharmaceutical it's necessary to duplicate the biological effects as well, which is far more complicated.
Additionally, creating a substitute cola recipe only requires mimicking the taste and physical characteristics. When reverse engineering a pharmaceutical it's necessary to duplicate the biological effects as well, which is far more complicated.