Alestramustine is the l-alanine ester form of estramustine, a combination of the nitrogen mustard normustine coupled via a carbamate to estradiol, with antineoplastic activity. Upon conversion of alestramustine to estramustine, estramustine binds to microtubule-associated proteins (MAPs) and beta tubulin, thereby interfering with microtubule dynamics and leading to microtubule disassembly and cell cyle arrest. Due to the estrogen moiety, this agent is able to selectively bind to and be taken up by estrogen receptor-positive cells.

Clentiazem is a chloride derivative of diltiazem, originated in Tanabe Seiyaku. It works as a blocker of calcium channels. The drug was investigated in the clinical trials for the treatment of stable angina, and essential hypertension. Despite the positive results of clinical trials, no development of the drug was reported.

Pyrroliphene is a dialkylaminodiphenylbutanol ester with antitussive and analgesic activities. In clinical trials the major side effect of Pyrroliphene was sedation, and the other side effect liabilities were similar to those of morphine.

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

Mespirenone (ZK 94679, 15β,16β-methylene-spironolactone) is a steroid aldosterone antagonist. In addition, it is a quite specific inhibitor of adrenocortical mineralocorticoid synthesis. In rodents mespirenone effectively prevents aldosterone-induced hypertension. It exerts natriuretic efficacy. Although it reached phase II clinical trials, it was discontinued in 1989.

Diacetamate (Acetaminophen Acetate, Acetaminophen Impurity, diacetyl-p-aminophenol) is a acetaminophen synthetic impurity. Acetaminophen-aspirin mixtures have lower stability due to acetylation of the former by the latter, producing diacetyl-p-aminophenol.

Budiodarone is a chemical analog of amiodarone with mixed ion channel electrophysiological activity. Budiodarone was developed to capitalize on the proven efficacy of amiodarone and to avoid its side effects. Budiodarone has a short plasma half-life (7 h) and a lower volume of distribution (13 L/kg). It is cleared from the body in 48 h. Like amiodarone, Budiodarone has balanced, multiple cardiac ion channel inhibiting activity, giving it properties of all four Vaughan Williams antiarrhythmic drug classes. Budiodarone, unlike amiodarone, undergoes rapid metabolism by plasma and tissue esterases. In clinical trials, Budiodarone effectively reduces the number and duration of atrial tachycardia/atrial fibrillation episodes.

Rifametane (SPA-S-565) is a semisynthetic derivative of rifamycin (a natural antibiotic produced by Amycolatopsis rifamycinica). It was being evaluated for treatment of bacterial infections. A phase I study showed that administration of rifametane is safe with minor, reversible adverse events such as mild headache, metallic taste and slightly elevated temperature for 3 to 4 hours. Rifametane has anti-tuberculosis activity and was suggested to be a good candidate for phase II clinical trials.

Siratiazem [LRA 113] is a calcium channel antagonist that is structurally similar to diltiazem but has a branched alkyl group on the basic nitrogen. Siratiazem has been developed in an attempt to limit the in vivo N-demethylation that is known to occur with diltiazem. Preliminary binding and functional studies in cardiac and vascular tissues indicate that it not only binds to diltiazem binding sites but also exhibits Ca2+ channel blocking properties comparable to diltiazem. Siratiazem has a similar profile of activity to its parent compound, diltiazem, in that it blocks calcium channels in vascular, intestinal smooth muscle and cardiac tissue, and is least potent in cardiac muscle. At higher concentrations, siratiazem may also block cardiac sodium channels.

Brovanexine is a derivative of bromhexine used as an adjunct to antibacterials in preparations for the treatment of respiratory-tract infections. Oral administration of brovanexine hydrochloride (BR-222) caused a significant increase in the output volume of respiratory tract fluid. Brovanexine at 10 and 20 mg/kg showed a tendency to reduce the viscosity of respiratory tract fluid in anesthetized dogs. Brovanexine also showed a tendency to reduce the viscosity of sputum obtained from the SO2-exposed rabbits.