Guaithylline (or Guaifylline), a xanthine derivative that was studied as a bronchodilator and expectorant, however, has never been marketed.

Prodolic acid is an indole derivative patented by American Home Products Corp. as antiinflammatory agent. Prodolic acid acts as non-steroidal anti-inflammatory compound and inhibits bradykinin-induced bronchoconstriction but did not affects histamine-induced bronchoconstriction in the guinea pig. In preclinical studies, Prodolic acid exhibits potent anti-inflammatory activity in adjuvant arthritic rats.

Rolodine (BW 58-271) is a pyrrolopynimidine. This compound has been described in the 1960’s as a potent hypnotic agent and a skeletal muscle relaxant. Rolodine has a local anesthetic effect when applied to the isolated frog sciatic nerve and blocks spontaneous electrical activity (as measured by EEG) lasting for several minutes in cats. No information is available on current use of this central nervous system depressant.

Gallium-68 is a positron-emitting radioisotope that is produced from a 68Ge/68Ga generator. Gallium-68-labeled peptides have been recognized as a new class of radiopharmaceuticals showing fast target localization and blood clearance. Because of the convenient half-life of 68Ga and the fact that it is generator-produced and therefore more widely available, considerable interest lies in the development of 68Ga-labeled imaging agents. Dotatate gallium (Ga-68) is a somatostatin-2 receptor analog which is radiolabeled with gallium 68 as a positron-emitting radioisotope. Dotatate gallium 68 is one of the most prominent radiopharmaceuticals used in imaging with positron emission tomography. It binds to the somatostatin-2 receptor which is usually overexpressed in many neuroendocrine tumors in both adult and pediatric patients. Gallium-68 (Ga-68)-based tracers are easily available, relatively cost-effective, and have relative ease of labeling. Over the past few years, the development of Ga-68-based tracers has exploded with a recent growing interest in infection and inflammation imaging. An estimated ~10,000 scans are being performed yearly in Europe at about 100 centers utilizing 68Ga-labeled somatostatin analogs within clinical trials.

Dysprosium (Dy), chemical element, a rare-earth metal of the lanthanide series of the periodic table. Dysprosium has no biological role. It is considered to be moderately toxic. Dysprosium is good at absorbing neutrons and so it is used in dysprosium-oxide-nickel cement in control rods in nuclear reactors. Dysprosium is used in data storage applications such as compact discs and hard discs. It is also used in medium source rare-earth lamps (MSRs) in the film industry. Dysprosium iodide is used these lamps to produce an intense white light. Dy-164 has two medical applications. It is used in the production of Dy-165, which is used in arthritis therapy. Dysprosium isotope Dy-164 is also used for the production of Dy-166, which decays to Ho-166 and this used in cancer therapy.

Scandium is a soft, silvery transition element which occurs in rare minerals from Scandinavia. It develops a slightly yellowish or pinkish cast when exposed to air.Scandium is one of the rare chemicals, that can be found in houses in equipment such as colour televisions, fluorescent lamps, energy-saving lamps and glasses. The use of scandium is still growing, due to the fact that it is suited to produce catalysers and to polish glass. The main application by volume is in aluminium-scandium alloys for the aerospace industry and for sports equipment (bikes, baseball bats, etc.) which rely on high performance materials. It has been shown to reduce solidification cracking during the welding of high strength aluminium alloys. Certain isotopes of Scandium is used in cancer treatments. Scandium possesses two radionuclides emitting b+ radiations (44Sc or 43Sc) that become appropriate candidates in positron emission tomography/computed tomography (PET/ CT) diagnosis, due to the half-life of around 4 h and decay to the nontoxic Ca. For both radionuclides, the half-life is compatible with the pharmacokinetics of a fairly wide range of targeting vectors (such as peptides, antibodies, antibody fragments, and oligonucleotides). The validity, usefulness, and advantages of 44Sc have been demonstrated by examples featuring 44Sc-radiolabeled targeting vectors, including 44Sc-radiopharmaceuticals very recently used in patients. Finally, 47Sc is a low energy bemitter which is suitable for single photon emission computed tomography (SPECT) and planar imaging. 47Sc can be also used for targeted radionuclide therapy, opens the field of Sc-based vectors from diagnosis to therapy, and gives a great opportunity for dosimetric calculations and for the development of personalized medicine. 46Sc is used in isotope-carrying antibodies for bonding with tumor associated cell surface antigens (substances that causes the production of an antibody when introduced into the body, e.g., toxins, bacteria, and viruses). 46Sc is added to DTPA-derivatized (process by which a compound is chemically changed, producing a new compound that has properties more amenable to a particular analytical method) monoclonal antibodies and has been shown to target tumor cells, specifically in vivo,where it accumulates to high levels in the tumor.

Epipropidine is an alkylating diamine bis-epoxide with antineoplastic activity.

Oxamarin was developed as a hemostatic agent. Information about the current use of this compound is not available.

Talampanel (TLP) was developed as a noncompetitive (allosteric) antagonist of the AMPA receptor. Talampanel does not act directly on the AMPA receptor, but at an allosteric site referred to as the GYKI receptor. Talampanel is being studied in the treatment of brain tumors and other brain disorders, such as epilepsy, Parkinson disease, amyotrophic lateral sclerosis, dyskinesias, glioblastoma, multiple sclerosis. It is a type of AMPA receptor antagonist. Dizziness has been the most commonly reported adverse event, with some sedation and ataxia, drowsiness and headaches reported at higher doses.

Cyprolidol is a pyridylcyclopropane derivative, developed by Neisler Laboratories. In animal models, cyprolidol produced an antidepressant effect qualitatively similar to those produced by imipramine. The compound blocked the tyramine-induced rise in blood pressure only in anesthetized dogs but potentiated it in conscious dogs. In man, cyprolidol was less effective than imipramine.