Etorphine was the first potent opiate agonist employed primarily for use in non-domestic and wild species. Etorphine was 500 times as potent as morphine, with a very rapid onset and short duration of action. In morphine-dependent subjects, etorphine suppressed abstinence but for a shorter period than morphine. Etorphine is a full opiate agonist and binds to multiple opiate sites in the central nervous system. It is believed to produce its clinical effects through binding the µ-, δ-, and κ- opiate sites. It has a potent effect on depressing the respiratory centers of the CNS thus resulting in apnea being commonly seen in immobilized animals. Etorphine revolutionized the ability of biologists and veterinarians to safely capture and restrain many species that previously could not be handled. Etorphine is not currently commercially available due to lack of production by the manufacturer.

Merafloxacin (CI 934) is a quinolone antibacterial. It is an inhibitor of Type II DNA topoisomerase. It demonstrated excellent activity against gram-positive organisms, including Corynebacterium sp. In addition, although the activity of merafloxacin against gram-negative bacilli was less than that reported for similar agents, it was comparable to that of aminoglycosidic aminocyclitol antibiotics. Merafloxacin development has been discontinued.

Adarotene (ST1926) is a new pro-apoptotic and cytodifferentiating antitumour drug, belongs to the so-called class of atypical retinoids. Adarotene is active on its own or in combination with other chemotherapeutics for the treatment of a vast number of experimental tumors. It was found in preclinical investigations the potential therapeutic use it in chronic myeloid leukemia (CML), against Rhabdomyosarcoma and for treatment of Adult T-cell leukemia/lymphoma (ATL). ST1926 induced an early DNA damage response, which led to increase in apoptosis, in addition to S-phase cell cycle arrest and a reduction in protein levels of the cell cycle kinase CDK1. The presence of the phenolic hydroxyl group on adarotene structure allows a rapid O-glucuronidation as a major mechanism of elimination of the drug, favoring a fast excretion of its glucuronide metabolite in the urines.

British Biotech was developing solimastat [BB 3644], an inhibitor of tumour necrosis factor and matrix metalloproteinase, as a potential treatment for colorectal cancer, inflammatory bowel diseases and rheumatoid arthritis. BB-3644 is an oral, broad-spectrum matrix metalloproteinase inhibitor (MMPI) structurally related to marimastat and BB-94. It is also >10-fold more active than marimastat in inhibiting the processing of cell-bound TNF-alpha. Solimastat development has been discontinued due to significant musculoskeletal toxicity.

Y-700 (Niraxostat or 1-[3-Cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid) is an inhibitor of xanthine oxidoreductase. Y-700 demonstrated high oral bioavailability being predominantly eliminated via the liver. It potently reduces serum uric acid levels. Y-700 was in clinical trials for the treatment of gout.

Alamifovir is a novel antiviral agent which was under development with Mitsubishi Pharma Corporation in Japan as a potential treatment for hepatitis B (HBV). Alamifovir and its hydrolyzed derivatives have shown preclinical efficacy activity against wild-type and lamivudine-resistant hepatitis B virus. The effective concentration of alamifovir required to reduce replication by 50% (EC50) for the wild-type was 0.027 uM, which is approximately 20 times less than lamivudine, and the EC50 for the lamivudine-resistant mutants was 2.6 to 3.3 uM. The mechanism of action of alamifovir appears to be via the inhibition of the protein priming reaction and the packaging reaction, thereby decreasing HBV replication. Alamifovir`s development has been discontinued.

Actinoquinol is sunscreen agent that absorbs Ultraviolet B light. Actinoquinol in combination with hyaluronic acid drops might be helpful for the human eye in the defense against photooxidative and other oxidative processes.

Razupenem (also known as PZ-601 or PTZ601) is an anti-MRSA carbapenem antibiotic. It is active against Enterobacteriaceae and Gram-positive bacteria including methicillin-resistant staphylococci and enterococci, and was investigated as potential alternative drug (replacing common antibiotics) against resistant bacteria. In healthy male volunteers, razupenem did not cause serious adverse events. The potential effect and safety of razupenem has been evaluated in a phase II clinical trial studying skin infection.

Volinanserin (MDL-100,907) is a highly selective 5-HT2A receptor antagonist. It is widely used in scientific research to investigate the function of the 5-HT2A receptor. Volinanserin is also being trialed as a potential antipsychotic, antidepressant and treatment for insomnia. Volinanserin (M-100907) was in phase III trials for chronic schizophrenia. In August 1999, development was discontinued for acute schizophrenia (schizoaffective disorder) on the basis of poor results. M-100907 is also active in animal models involving blockade of NMDA glutamatergic channel receptors, an effect known to resemble some behavioral symptoms of schizophrenia in man. M-100907 is also claimed in other patents for the treatment of thromboembolic disorders, for the treatment of various developmental neurological disorders such as autism and attention deficit hyperactivity disorder.

Tibeglisene (also known as BM 13907) is a pentynoic acid derivative patented by Boehringer Mannheim G.m.b.H. as insulin sensitizer with hypoglycemic activity. Tibeglisene is also able to reduce serum triglyceride and cholesterol concentrations. Tibeglisene exerts favor influences on glucose-transport activity.