Bioequivalence Study to Compare Bosentan 32 mg Dispersible Tablets Versus Tracleer® 32 mg Tablets

Inclusion Criteria: * The subject is male \& aged between eighteen to forty-five years (18 - 45), both inclusive. * The subject is within the limits for his height \& weight as defined by the body mass index range (18.5 - 30.0 Kg/m2). * The subject is willing to undergo the necessary pre- \& post- medical examinations set by this study. * The results of medical history, physical examination, vital signs \& conducted medical laboratory tests are normal as determined by the clinical investigator. * The subject tested negative for Hepatitis B (HBsAg), Hepatitis C (HCVAb) and human immunodeficiency virus (HIVAb). * There is no evidence of psychiatric disorder, antagonistic personality, and poor motivation, emotional or intellectual problems likely to limit the validity of consent to participate in the study or limit the ability to comply with protocol requirements. * The subject is able to understand and willing to sign the informed consent form. * The subject has normal cardiovascular system, pulmonary system \& ECG recording. * The subject kidney and liver functions (AST \& ALT enzymes) tests are within normal range. * The subject blood pressure is ≥ 110/70 mmHg before dosing. Exclusion Criteria: * The subject is a heavy smoker (more than 10 cigarettes per day). * The subject has suffered an acute illness one week before dosing. * The subject has a history of or concurrent abuse of alcohol. * The subject has a history of or concurrent abuse of illicit drugs. * The subject has a history of hypersensitivity and/or contraindications to the study drug and any related compounds. * The subject has been hospitalized within three months before the study or during the study. * The subject is vegetarian. * The subject has consumed caffeine or xanthine containing beverages or foodstuffs within two days before dosing and until 48 hours after dosing in both study periods. * The subject has taken a prescription medication within two weeks or even an over the counter product (OTC) within one week before dosing in each study period and any time during the study, unless otherwise judged acceptable by the clinical investigator. * The subject has taken grapefruit containing beverages or foodstuffs within seven (7) days before first dosing and any time during the study. * The subject has been participating in any clinical study (e.g. pharmacokinetics, bioavailability and bioequivalence studies) within the last 80 days prior to the present study. * The subject has donated blood within 80 days before first dosing. * The subject has a history or presence of cardiovascular, pulmonary, renal, hepatic, gastrointestinal, hematological, endocrinal, immunological, dermatological, neurological, musculoskeletal or psychiatric diseases. * The subject has consumed any drugs that may affect pharmacological or pharmacokinetic properties of Bosentan. (for example: fluconazole, amiodarone, ketoconazole, itraconazole, amprenavir, erythromycin, fluconazole, diltiazem, Cyclosporine A, Glyburide, Norethindron, Ethinyl estradiol, Simvastatin, lopinavir, ritonavir, Rifampin) two weeks before and after the study and during the study. * The subject suffer from phenylketonuria disorder.