Ufiprazole (Omeprazole sulfide) is a metabolite of Omeprazole, which is a proton pump inhibitor. Omeprazole sulfide has been shown to be a direct-acting inhibitor of CYP2C19 in pooled human liver microsomes. Ufiprazole is also a weak BRS-3 agonist.

Irosustat is a first-generation, orally active, irreversible steroid sulfatase inhibitor. It did not stimulate the growth of estrogen-sensitive MCF-7 breast cells in vitro. Irosustat was in phase II clinical trials for the treatment of breast cancer and endometrial cancer and phase I clinical trial for the treatment of prostate cancer. However, this research has been discontinued.

Bisphenol A is a small estrogenic monomer that is polymerized to produce polycarbonate plastic and resins used to line metal cans. It is also used to make some dental sealants. Bisphenol A had been considered to be a very weak environmental estrogen. It is able to interact with human estrogen receptors. In addition, it binds strongly to the estrogen-related receptor gamma. Bisphenol A inhibited androgen-induced androgen receptor transcriptional activity. Prenatal exposure to maternal Bisphenol A concentrations were related to higher levels of anxiety, depression, aggression, and hyperactivity in children. Bisphenol A exposure in childhood was associated with higher levels of anxiety, depression, hyperactivity, inattention, and conduct problems. It never found use as a drug.

Toloconium methylsulphate is a quaternary ammonium antiseptic which has been used in infections of the mouth.

Roxolonium, a derivative of glycyrrhetic acid, was studied as an antiulcer agent. Information about the further development of this compound is not available.

Ciclafrine is azaspiroalkane derivative patented by pharmaceutical company Goedecke A.-G. for the low blood pressure treatment

Celivarone is a benzofuran derivative with a multifactorial mode of action including class IV Vaughan Williams’ electrophysiological as well as anti-adrenergic properties. It has no iodine and has a limited tissue accumulation compared with amiodarone. Celivarone exhibits effective anti-arrhythmic properties in several ventricular ischemia- or reperfusioninduced arrhythmia models as well as in in vitro and in vivo atrial fibrillation (AF) models. Its electrophysiological properties are similar to amiodarone (multifactorial mode of action) but with different relative effects on the ion channels. At the ventricular level, celivarone shows anti-arrhythmic activities by suppressing reperfusion-induced arrhythmias (i.v. and oral routes) and reducing the early mortality due to myocardial infarction (oral route) in rats models. At the atrial level, celivarone is effective in atrial fibrillation models with restoration of sinus rhythm or prevention of AF induction and AF recurrence.

Diacetolol is the major metabolite of the β-adrenoceptor blocking agent, acebutolol. In vitro, the β-adrenoceptor blocking potency of diacetolol was less than that of acebutolol but its cardioselectivity (atrial relative to tracheal tissue) was greater. Diacetolol had weak intrinsic sympathomimetic activity, and no significant membrane-stabilizing activity. It did not restore sinus rhythm to anaesthetized dogs with ouabain-induced arrhythmias but was similar to acebutolol in preventing arrhythmia induced by adrenaline/methylchloroform in anaesthetized cats. Study of diacetolol pharmacokinetics and bioavailability suggests either a first-pass effect or incomplete absorption of diacetolol after oral administration. Diacetolol plasma half-life after oral administration is about 12 h and is not dose-dependent. Diacetolol possesses significant antihypertensive action against moderate essential hypertension in man. Its antihypertensive effect is associated with a reduction in the heart rate and a decrease in plasma renin activity.

CS-834 is a beta-lactam antibiotic of a carbapenem class, developed by the Japanese company Sankyo Co. Ltd. CS-834 is an ester-type prodrug of the active metabolite R-95867. The drug showed potent and well balanced antibacterial activity as well as stability against dehydropeptidase-I. The in vivo efficacy of CS-834 was evaluated in murine systemic infections caused by 16 strains of gram-positive and -negative pathogens. The efficacy of CS-834 was in many cases superior to those of cefteram pivoxil, cefpodoxime proxetil, cefdinir, and cefditoren pivoxil, especially against infections caused by S. aureus, penicillin-resistant S. pneumoniae, E. coli, Citrobacter freundii, and Proteus vulgaris. Pharmacokinetics of CS-834 was evaluated in healthy male volunteers, but no further clinical development of the drug was reported.

Metaclazepam is a benzodiazepine derivative. It exerts anxiolytic properties.