Olpadronate, a nitrogenated bisphosphonate that can inhibit bone resorption. Although it shares the therapeutic and pharmacological properties of pamidronate and alendronate, it has a greater dosage amplitude, more predictable effects, and greater digestive tolerability than other bisphosphates. Clinical trials have shown that the oral olpadronate was well tolerated and effective in the treatment of Paget's disease. In addition, the drug is ongoing in phase II clinical trials in the Netherlands. This clinical trial has to assess the efficacy of the intravenous drug in decreasing the average back pain intensity from baseline.

Pobilukast is the Leukotriene D4 receptor antagonist. Pobilukast significantly attenuated the Salmonella enteritidis endotoxin-induced thrombocytopenia but had no effect on either the endotoxin-induced early leukopenia or late leukocytosis. Additionally, Pobilukast significantly reduced the endotoxin-induced hemoconcentration and improved survival to 30% at 48 hr. Pobilukast dose-dependently inhibited the immediate hemodynamic changes after leukotriene D4 (LTD4) injections. Pobilukast also attenuated the increase in vascular permeability and the prolonged decrease in CO, suggesting that the observed cardiac and vascular effects of LTs were mediated by stimulation of LT receptors. A shift toward the right of the dose-response curves to histamine with pobilukast compared to that with placebo in three subjects was demonstrated, whereas the active compound did not exhibit any protective effect against histamine in the remaining nine subjects. It was concluded that there is a leukotriene component to the bronchial responses to histamine in some, but not all, subjects. Pobilukast had been in phase II clinical trial for the treatment of asthma. However, this development was discontinued.

Tigemonam is a dialkylazetidinone derivative patented by E. R. Squibb and Sons, Inc. as a beta-lactam agent useful for the treatment of bacterial infections. Of the orally active beta-lactams, tigemonam is one of the most potent, with a spectrum of activity similar to that of aztreonam and highly resistant to hydrolysis by the beta-lactamase enzymes. Tigemonam inhibits 90% of Escherichia coli, Klebsiella spp., Proteus spp., Salmonella spp., Haemophilus influenzae and Branhamella catarrhalis tested. In localized infections, tigemonam also demonstrated excellent in vivo activity. In acute pyelonephritis in mice caused by Escherichia coli or Proteus sp., tigemonam was very effective. In a rat lung model with Klebsiella pneumoniae, tigemonam was active with a median effective dose of 46 mg/kg compared with 160 mg/kg for cefaclor and over 200 mg/kg for amoxicillin.

Chromocarb is benzo-γ-pyrone derivative with vasoprotection activity used to eliminate lipoperoxidation post-vitrectomy. Peroral treatment of rats with chromocarb significantly reduced the degradation of the vascular wall by intravenous collagenase, as demonstrated by a lesser permeability increase of the blood-brain barrier, a shorter recovery time, lower hydroxyproline levels in the cerebrospinal fluid and a lesser decrease of the collagen content of the brain capillary basal lamina.

Tubulozole is a stereospecific microtubule inhibitor. Structurally it is related to the benzimidazole carbamates by its carbamate moiety, which is essential for the activity of both types of compounds. The compound exists as a cis-isomer called tubulozole-C (R 46 846) and as a trans-isomer called tubulozole-T. The cis-isomer appears to be a potent and specific microtubule inhibitor, the trans-isomer being inactive at 100 times higher concentrations. At low concentrations, both isomers of tubulozole (C, T) inhibit Plasmodium falciparum but only tubulozole C inhibits mammalian cells. Since tubulozole C prevents polymerization of mammalian tubulin whereas tubulozole T does not, the antimalarial action of tubulozoles may not involve microtubules. Tubulozole-C, a new synthetic anticancer drug, interfered with the structure and function of microtubules in both interphase and mitotic cells. The activity of Tubulozole-C in experimental tumor systems can be explained partly by a direct antimitotic effect and partly by the disintegration of the normal subcellular organization of the nondividing cells. At concentrations which affect the microtubule system, tubulozole-C arrested directional migration of transformed cells and malignant invasion in a three-dimensional organ culture system. Investigations in vivo show that malignant L1210 leukemia cells are more susceptible to the antimicrotubular effect of tubulozole-C than are the normal leukocytes of the host. The trans-isomer of tubulozole (tubulozole-T, R 48 265), which has no antitumor activity in vivo, did not affect the microtubule system of cells in vitro or their capacity for directional migration or for malignant invasion.

Piridronic acid is pyridinyl bisphosphonate. It is the bone calcium metabolism regulator. Piridronic acid was used for the treatment of osteoporosis. It is the human farnesyl pyrophosphate synthase inhibitor. When expressed on an actual or anticipated clinical dose basis for osteoporosis piridronic acid may have a greater potential for inducing gastric damage than do pyridinyl bisphosphonates. Piridronic acid induced significantly more antral damage than risedronate and a greater number of lesions compared to pamidronate and risedronate.

Celgosivir is a butanoyl ester derivative of castanospermine, a compound derived from the Australian chestnut with activity against hepatitis C virus. Celgosivir rapidly converts to castanospermine in the body, where it is a potent inhibitor of alpha-glucosidase I, a host enzyme required for viral assembly, release, and infectivity.

JNJ-872 is an inhibitor of influenza virus replication that offers a potential for the treatment of pandemic and seasonal influenza.