combination of Drug_Type_Subclass , Drug_Type , and Drug_Class . For example: Sildenafil is a "synthetic small molecule therapeutic" Abciximab is a "monoclonal antibody biological therapeutic". Vitamin D3 is a "natural product-derived small molecule supplement". Ioflupane 123I is a "synthetic small molecule imaging agent"  Any feedback, pointers to any existing classifications/taxonomies, etc. would