Dexniguldipine (B8509-035, (-)-(R)-niguldipine) is a new dihydropyridine derivative, that exerts selective antiproliferative activity in a variety of tumor models and, in addition, has a high potency in overcoming multidrug resistance. Dexniguldipine is ( - )-(R)-enantiomer of niguldipine, of which the ( )-(S)-enantiomer shows pronounced cardiovascular hypotensive activity due to its high affinity for the voltage-dependent Ca2 channel. As compared with the (S)-enantiomer, the (R)-enantiomer has a 40-fold lower affinity for the Ca 2 channel and, accordingly, only minimal hypotensive activity in animal pharmacology models. Dexniguldipine have shown antiproliferative activity in several tumor cell lines, but the concentrations necessary to inhibit growth have varied by several orders of magnitude between cell lines. Initial results of preclinical investigations for the evaluation of the mechanism of its antiproliferative activity demonstrate that dexniguldipine interferes with intracellular signal transduction by affecting phosphoinositol pathways, protein kinase C expression, and intracellular Ca 2 metabolism. In a series of human tumor xenografts in vitro, dexniguldipine demonstrated selective antiproliferative activity against several tumor types, e.g., melanoma and renal-cell carcinoma. Striking results were obtained in a hamster model, in which neuroendocrine lung tumors could be completely eradicated by 20 weeks of oral treatment with 32.5mg/kg dexniguldipine, whereas Clara-cell-type lung tumors were not affected. In in vitro studies, dexniguldipine has been found to bind to P-glycoprotein (P-gp) and to enhance the cytotoxicity of chemotherapeutic agents such as doxorubicin and etoposide in several cell lines The synergistic effect may well be associated with the reversal of multidrug resistance (MDR) related to the activity of P-gp. In the clinical therapy of cancer, resistance to many cytostatic drugs is a major cause of treatment failure. However, the high potency of dexniguldipine (about 10-fold as compared with that of verapamil in vitro) and its low cardiovascular activity provide the opportunity to achieve blood or tumor concentrations that might be high enough to overcome Mdr 1 resistance in patients without producing dose-limiting cardiovascular effects.

Nibroxane, 5-bromo-2-methyl-5-nitro-m-dioxane, is a topically effective antimicrobial agent with a broad spectrum of activity. Nibroxane is unusual in that it not only possesses high microbiocidal activity against Gram positive (Staphylococcus uureus) and Gram negative (Pseudomonas aeruginosa) bacteria but also against yeasts (Candida albicans) and moulds (Aspergillus niger). In addition, the 5-bromo-5-nitro-m-dioxanes have, as a class of compounds, the distinct advantage of being chemically stable over a wide pH range. This inherent stability, coupled with its broad spectrum of microbiocidal activity, makes nibroxane an excellent candidate as a preservative for cosmetic and pharmaceutical formulations.

LEVOFENFLURAMINE is a levorotatory enantiomer of fenfluramine, a substituted amphetamine which was formerly used to treat obesity. LEVOFENFLURAMINE has dopamine-antagonistic properties and, at high doses, increases dopamine concentrations in rat striatal dialysates. It is essentially inactive to reduce food intake in human subjects.

Mideplanin (MDL 62873), a teicoplanin amide derivative, was studied as an antibacterial agent against Gram-positive bacteria. However, further, development appears to have been discontinued.

Profadol is a pyrrolidine derivative patented in the 1960s by pharmaceutical company Parke-Davis as opioid analgesic. Profadol acts as a mixed agonist-antagonist of the μ-opioid receptor and in preclinical studies, Profadol precipitates abstinence in morphine-dependent monkeys and can reverse pethidine- induced narcosis in nondependent monkeys. In morphine-dependent human subjects, Profadol was also found to pre¬cipitate acute abstinence syndromes, with a potency 40 to 50 times less than that of nalorphine. Profadol, unlike other morphine-antagonists, does not produce nalorphine-like subjective effects. Over a fourfold range of doses, this drug was found to produce subjective effects indistinguishable from those of morphine. Also unlike other morphine-antagonists, profadol is quite active on the "classical" rodent tests for analgesia. It is about 1.3 times as potent as pethidine on the mouse hot-plate test, and about four times as potent on the rat tail-pressure test.

Toluidine Blue (also known as tolonium chloride or Toluidine blue O) is metachromatic dye used for a variety of histological staining, it selectively stains acidic tissue components (sulfates, carboxylates, and phosphate radicals. Toluidine blue has an affinity for nucleic acids, and therefore binds to nuclear material of tissues with a high DNA and RNA content. It was evaluated the toluidine blue staining in premalignancies, and superficial oral ulceration suggesting malignancy. The study showed 100% sensitivity in the detection of in situ and invasive carcinoma and no false-negative results occurred. The lesions that were diagnosed as dysplasia did not retain stain, and thus gave false-negative results. The reasons could be that the exact mechanisms by which the dye differentially stains malignant or dysplastic tissues remain unknown.

Fluridone, an herbicide that used for controlling invasive aquatic plants such as hydrilla in surface water bodies. It inhibits carotenoid synthesis in targeted plant species, preventing photosynthesis and ultimately causing mortality. This compound contains a 4(1H)-pyridone and a trifluoromethyl-benzene moiety, which are also present in molecules with analgesic and anti-inflammatory properties. Experiments on rodents have confirmed that fluridone could represent a new prototype of an anti-inflammatory drug.

8-Hydroxy-7-iodo-5-quinolinesulfonic acid (Ferron) showed fungistatic effect for Candida and for M. canis and T. mentagrophytes. Resotren is a chemical combination of chloroquine and iodohydroxyquinoline and, taken by mouth, is poorly absorbed and reaches the lower bowel in considerable concentration. Resotren is effective in both intestinal and extra-intestinal amoebiasis. Al-Ferron timed spectrophotometry assay is a basic method in the study on the formation of polynuclear hydroxyl aluminum species and their transformation laws in aqueous systems.

Tiapamil (also known as Ro 11-1781) is a dithiane derivative patented by Hoffmann-La Roche, F., und Co., A.-G. as calcium-channel antagonist useful for myocardial infarction treatment. Tiapamil, like verapamil, inhibited in a concentration-dependent manner Ca2+-induced contractions in isolated, K+-depolarized preparations of rat renal artery, dog coronary artery and rabbit main pulmonary artery. The inhibitory effects of Tiapamil can be overcome by raising the Ca2+ concentration of the bath fluid. In the rabbit main pulmonary artery, Tiapamil reduces 45Ca influx into the K+-depolarized vascular smooth muscle cells. Tiapamil inhibits the slow potentials in partially depolarized guinea-pig papillary muscles. Tiapamil decreases contractile force in isolated guinea-pig atria and papillary muscles, as well as in isolated cat hearts. Tiapamil also reduces heart rate and increases coronary flow in these preparations. Tiapamil doubled coronary artery blood flow in the coronary sinus blood without producing major changes in blood pressure and heart rate in anesthetized dogs. Tiapamil did not affect contractions of isolated guinea-pig ileum, rat stomach strips or rat vas deferens in response to various stimulants. Tiapamil have no major effects on renal water and electrolyte excretion, on autonomic nerves and receptors, on pain perception and on the central nervous system. Acute, subacute, and chronic toxicity studies demonstrate low toxicity for Tiapamil with no tendency for accumulation. In clinical trials, Tiapamil effectively lowers systolic and diastolic blood pressure, but have no effects on heart rate