Described are various methods for stabilizing pharmaceutical formulations of a specific Hepatitis C Viral (HCV) inhibitor against the formation of a particular genotoxic degradation product. Such methods include temperature control, moisture control, excipient control, capsule shell control, basification and a reconstitution approach.本發明闡述用於使特異性C型肝炎病毒(HCV)抑制劑之醫藥調配物穩定以對抗特定遺傳毒性降解產物形成之多種不同方法。此等方法包括溫度控制、水分控制、賦形劑控制、膠囊殼控制、鹼化及復水等方式。