The purpose of this study is to determine the pharmacokinetic and safety profiles of an experimental HCV protease inhibitor with and without ritonavir in healthy volunteers.

Inclusion Criteria:

• overall healthy subjects
• non-childbearing potential females included

Exclusion Criteria:

• history of significant sensitivity to any drug
• positive test for HAV IgM, HBsAg, anti-HCV Ab or anti-HIV Ab
• history of gastrointestinal issues or procedures
• history of seizures, diabetes or cancer (except basal cell carcinoma)
• clinically significant cardiovascular, respiratory (except mild asthma), renal, gastrointestinal, hematologic, neurologic, thyroid, or any uncontrolled medical illness or psychiatric disorder
• use of tobacco or nicotine-containing products with the 6-month period prior to study drug administration
• donation or loss of 550 mL or more blood volume or receipt of a transfusion of any blood product within 8 weeks prior to study drug administration
• abnormal screening laboratory results that are considered clinically significant by the investigator
• current enrollment in another clinical study
• previous enrollment in this study
• recent (6-month) history of drug/alcohol abuse that could preclude adherence to the protocol
• pregnant or breastfeeding female
• requirement for any OTC and/or prescription medication, vitamins and/or herbal supplements on a regular basis