11 DESCRIPTION Bosentan, an endothelin receptor antagonist that belongs to a class of highly substituted pyrimidine derivatives, with no chiral centers. It is designated chemically as 4-tert-butyl-N-[6-(2-hydroxy-ethoxy)-5-(2-methoxy-phenoxy)-[2,2´]-bipyrimidin-4-yl]-benzenesulfonamide monohydrate and has the following structural formula: C 27 H 29 N 5 O 6 S•H 2 O M.W. 569.64 Bosentan is a white to yellowish powder. It is poorly soluble in water (1.0 mg/100 mL) and in aqueous solutions at low pH (0.1 mg/100 mL at pH 1.1 and 4.0; 0.2 mg/100 mL at pH 5.0). Solubility increases at higher pH values (43 mg/100 mL at pH 7.5). In the solid state, bosentan is very stable, is not hygroscopic and is not light sensitive. Bosentan is available as 62.5 mg and 125 mg film-coated tablets for oral administration, and contains the following excipients: corn starch, ethyl cellulose, glyceryl behenate, hypromellose, iron oxide red, iron oxide yellow, magnesium stearate, pregelatinized corn starch, povidone K90, sodium starch glycolate, titanium dioxide and triacetin. Each bosentan 62.5 mg tablet contains 64.541 mg of bosentan monohydrate, equivalent to 62.5 mg of bosentan base. Each bosentan 125 mg tablet contains 129.082 mg of bosentan monohydrate, equivalent to 125 mg of bosentan base. 1
⚠️ Warnings
• Caution should be exercised in patients with history of heart disease, liver disease and anemia.
• It may cause dizziness or drowsiness, do not drive a car or operate machinery while taking this medication.
• During the treatment monitor the level of hemoglobin regularly.
• Avoid pregnancy while taking this medication by using proper birth control methods.
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Patient may develop oligohidrosis(absence of sweating) or high body temperature. If it is so consult with your healthcare provider.
