Closantel is a synthetic anti parasitic agent which is highly effective against adults and larvae (6 to weeks old) of liver flukes (Fasciola hepatica), and against several important gastrointestinal roundworms (e.g. Bunostomum, Haemonchus, Oesophagostomum, Ostertagia - Teladorsagia, Strongyloides, Trichostrongylus), as well as against screwworms (maggots of Cochliomyia spp and Chrysomya spp), sheep nasal bots (Oestrus ovis), and sheep keds (Melophagus ovinus). The molecular mode of action closantel is not completely elucidated, but closantel decouples the mitochondrial oxidative phosphorylation, which leads to the inhibition of ATP synthesis, this seems to occur through suppression of the activity of succinate dehydrogenase and fumarate reductase, two enzymes involved in this process. Finally this all cause the death of the parasite. Recently it has been discovered that closantel also inhibits chitinase in Onchocerca volvulus, a filarial nematode causing river blindness in humans. Chitinase is an enzyme involved in larval molting. Its inhibition interrupts their development to adult worms. This drug possesses some side effects: hyper acute anaphylactic reactions in cattle; hypersensitivity reactions; overdoses can cause reduced visibility or blindness, anorexia, lack of coordination and general weakness.

Clopimozide is a typical antipsychotic drug, developed by Janssen Pharmaceutica. Clopimozide belongs to diphenylbutylpiperidine class of neuroleptics, and possess an extremely long duration of action. The drug acts by binding to dopamine receptors and by inhibition of calcium channels. In a clinical trial, clopimozide exhibited a marked effect on schizophrenic target symptoms, with an absence of sedation and a low degree of extrapyramidal side-effects. Despite positive results, the drug was never marketed.

Clinolamide (cyclohexylamine of linoleic acid) is a drug developed by a Japanese company Sumitomo Chemical Co. Ltd. Clinolamide has been found to lower serum and liver cholesterol levels and to reduce the severity of atherosclerosis in cholesterol-fed rabbits.

Cinoctramide a derivative of cinnamic acid. It was patented in 1967, and was claimed to act on a central nervous system as a harmonious tranquilizer, and possess anti-convulsive properties in the case of chemically or electrically induced cramps. No clinical development of cinoctramide was reported.

Cicortonide is a synthetic cyano-glucocorticoid with anti-inflammatory and antirheumatic, as well as antiallergenic properties.

Emicerfont (GW876008) is a nonpeptide vcorticotropin-releasing factor type 1 (CRF1) receptor antagonist. It was in clinical trials for the treatment of anxiety disorders, irritable bowel syndrome and major depressive disorder however development of emicerfont has been discontinued.

Duvoglustat, an alkaloid azasugar or iminosugar, is a biologically active natural compound that exists in mulberry leaves and Commelina communis (dayflower) as well as from several bacterial strains such as Bacillus and Streptomyces species. Duvoglustat is an investigational pharmacological chaperone for the treatment of acid α-glucosidase (GAA) deficiency, which leads to the lysosomal storage disorder Pompe disease, which is characterized by progressive accumulation of lysosomal glycogen primarily in heart and skeletal muscles. Duvoglustat possesses antihyperglycemic, anti-obesity, and antiviral features. Most importantly, pre-meal intake of duvoglustat in therapeutic concentration has resulted in the inhibition of postprandial hyperglycemia and hyperinsulinemia. Thus, duvoglustat seems to be a potential treatment for checking or setting back the inception of diabetes. No duvoglustat-related adverse events or drug-related tolerability issues were identified in phase II clinical trial for the treatment of Pompe disease.

Cinaciguat acts specifically on oxidized/haem-free soluble guanylyl cyclase by binding to the enzyme's haem pocket and mimicking the nitric-oxide-bound haem group. It is in clinical development for the treatment of acute decompensated heart failure. Cinaciguat had been in phase II clinical trials. However, trials were terminated early because of an excess of hypotension in the cinaciguat arms and subsequent slow enrolment.

Surinabant is a cannabinoid receptor type 1 antagonist developed by Sanofi-Aventis for the treatment for nicotine addiction and obesity. In preclinical models, Surinabant reduced body weight gain, as well as plasma glucose levels and triglycerides. Surinabant also reduced insulin and leptin secretion and increased adiponectin and corticosterone levels in rats. Phase I and phase II studies showed good clinical safety profiles in healthy subjects and in obese subjects, although doses higher than 10mg/day were associated with gastrointestinal events and sleep disorders.

Teglicar, an antihyperglycemic agent, is a carnitine palmitoyl-transferase 1 (L-CPT1) inhibitor that was studied for the treatment of type 2 diabetes. The drug participated in phase II clinical trial in Italy; however, the further development apparently was discontinued.