ABSTRACT
Torcitabine (beta-l-2′-deoxycytidine) (l-dC) is the beta-l-enantiomer of the natural nucleoside d-cytidine. This drug was developed as an antiviral agent for the treatment of chronic hepatitis B virus infection. Torcitabine had poor oral bio availability, but as its 3′,5′-divaline ester (val-l-dC) and its 3′-monovaline ester, valtorcitabine dihydrochloride, had excellent oral bioavailability, mainly the latter drug was developed for clinical use (Hodge, 2004).
