This is a single center open label randomized 4-period 2-sequence replicated crossover design study. A total of 52 healthy subjects will be randomized.

Serial blood samples will be obtained for PK evaluation.

Inclusion Criteria:

• All inclusion criteria must be satisfied within 30 days of enrollment and must be documented in the source documents.
• A healthy man or woman between the ages of 18 and 60
• Has no clinically significant findings in medical history, physical examination, EKG and vital signs
• Weighs > 45 kg (99 lbs.) and has body mass index (BMI) < 30 kg/m2
• Agrees to abstain from alcohol consumption for 48 hrs prior to dosing and for the duration of each of the study in-house periods
• Is a non-smoker or light smoker (no more than the equivalent of five cigarettes per day) and agrees to abstain from smoking for the duration of each of the study in-house periods

Exclusion Criteria:

• None of the exclusion criteria may be present for enrollment
• Known history (including family history) or symptoms of any clinically significant bleeding (i.e. a bleeding that required medical attention) or a vascular malformation
• Major surgery, severe trauma or bone fracture within 3 months of the first dose of the study drug or a planned surgery within 1 month after the last dose of the study drug
• History of blood donation of more than 500 mL within 3 months prior to the first dose of the study drug
• History of alcohol abuse (greater than 3 alcoholic beverages per day)
• Positive screen for drugs of abuse
• Positive serology test for HIV, Hepatitis B or C
• Has any allergy or sensitivity to fXa inhibitors