M oloy Mitra

  Bosentan is a dual endothelin receptor antagonist. It is used in the treatment of pulmonary artery hypertension (PAH). Endothelin receptor antagonists (ERAs) act on the endothelin pathway by blocking binding of endothelin-1 to its receptors [endothelin type-A (ETA) and/or type-B (ETB)] on the surface of endothelial and smooth muscle cells. Bosentan is licensed in the United States, the European Union and other countries by Actelion Pharmaceuticals for the management of PAH under the trade name Tracleer. Bosentan, is a non-peptide and orally active. Bosentan is highly protein-bound, with approximately 98% bound to albumin. This paper reviews the pharmacological and pharmaceutical properties of Bosentan. Bosentan could be an attractive target for the generic industries.

The present study deals with the dissolution of an angiotensin II receptor antagonist drug, candesartan. Candesartan cilexetil is a poorly water-soluble prodrug. The in vitro dissolution testing of Candesartan cilexetil in water and buffer solutions is not possible. In the present study, an attempt was made to develop a dissolution medium for in vitro testing of the drug. A Kromacil C18, 5µm column having 150x4.6 mm internal diameter in isocratic mode with mobile phase containing mixture of buffer (pH 4.5) and acetonitrile in ratio of 45:55 was used. The flow rate was 1.5 mL/min and effluents were monitored by UV at 257 nm. The selection of the medium was made on the basis of solubility data of Candesartan cilexetil in different dissolution medium at 37 °C. Solubility data revealed that phosphate buffer (pH 6.5) consisting of 0.35% w/v tween 20 could be a suitable dissolution medium. Key words: Candesartan, solubility, buffer, dissolution.