By API Standards
- Ralfinamide
- Ramelteon
- Ranitidine
- Ranolazine
- Rapamycin
- Rasagiline
- Rebamipide
- Regorafenib
- Relugolix
- Remdesivir
- Repaglinide
- Ribociclib
- Riboflavin
- Riociguat
- Risperidone
- Ritonavir
- Rivaroxaban
- Rivastigmine
- Rizatriptan
- Roflumilast
- Ropinirole
- Rosuvastatin
- Roxadustat
- RPR 121057
- RS 94287
- Rubber oligomer
- Rupatadine