The Adefovir Dipivoxil Liposome Research

This paper consists of five chaptersIn the first chapter, interaction between ADV and biomembrane was first outlined. Introduction about characteristics and development of targeted-drug delivery system and liposomes was made including targetability and low-toxicity.In the second chapter, physical-chemical properties of ADV such as insolubility and O-W dispersion coefficients were investigated. Stability of ADV is initially worked to make basis for formula and pharmacokinetics.In the third chapter, ADV liposomes were made using alcohol-injection. The effect of phospholipid types and drug/phospholipid ratios on degradation of liposomes in vitro and PSD was inspected. EE was determined by low-temperature ultracentrifiigation, which is higher than 90%. HPLC for determining the concent of ADV in liposomes was established.In the forth chapter, optimal freezing-drying technique and formula to make ADV liposomes was chosen out, stability of which was initially studied.In the fifth chapter, HPLC to determining ADV and PMEA in biological specimen was established, respectively. Degradation in vitro of ADV-S and ADV-L in different genus of animals was respected. The result showed that ADV degraded immediately in plasma and tissues. With PMEA as an index, the tissue distribution was investigated after vein shot injection of ADV-S, ADV-L and ADV-ML in mice, showing that after formula-change, targetability of ADV was apparently enhanced. Compared with common liposomes, long-circulation ones had more superiority, whose half-life and t_max were greatly prolonged.