Adefovir Dipivoxil/Lamivudine

This is a phase I study being conducted to support the clinical development program of a FDC product of the nucleoside analogue lamivudine and the nucleotide analogue adefovir dipivoxil. To establish bioequivalence, the exposure of lamivudine and adefovir dipivoxil when administered as the FDC will be compared to that of Heptodin (lamivudine) and Hepsera (adefovir dipivoxil) when administered separately. In this study, the FDC product will contain 100mg lamivudine/10mg adefovir dipivoxil.
Total 40 healthy adult subjects will be enrolled. The study will include a screening visit and two treatment sessions. The screening visit will be conducted up to 3 weeks prior to the first dose of Session 1. All subjects will receive Regimen A through B according to the randomization schedule. Eligible subjects will be enrolled in the study and randomized to receive the following treatment regimens in table below in one of the following treatment sequences: AB, or BA. There will be a seven to ten days washout period between each treatment session. Pharmacokinetic sampling for measurement of plasma lamivudine and adefovir dipivoxil concentrations will be conducted over a 48-hour period following the morning administration of study medication in each study session. During this time, all subjects will remain in the unit for pharmacokinetic (PK) sample collection. The total duration (from screening to the end of the study) of each subject's participation will be approximately four weeks.