As @Aloisius has already noted, pharma companies aren’t constrained to novel compounds in making a profitable drug. For example, GlaxoSmithKline (GSK) could create a sustained-release form of USP-grade psilocybin with a patented release mechanism, be it physical (capsuled pellets with staggered degrees of dissolubility) or chemical (binding the active drug to an amino acid that requires metabolic enzymes to cleave off).
It’s pretty common for a pharma company to create such a formulation once their patent for the active compound has expired (e.g. Lamictal --> Lamictal XR)
