Disclosed are formulation and optimization protocols for delivery of therapeutically effective amounts of biologically active agents to liver, tumors, and/or other cells or tissues. Also provided are compositions and uses for cationic lipid compounds of formula (I).The invention also relates to compositions and uses for stealth lipids of formula (XI).Also provided are processes for making such compounds, compositions, and formulations, plus methods and uses of such compounds, compositions, and formulations to deliver biologically active agents to cells and/or tissues.本發明揭示用於向肝臟、腫瘤及/或其他細胞或組織傳遞治療有效量之生物活性劑的調配及最佳化方案。亦提供式(I)之陽離子型脂質化合物的組合物及用途。本發明亦係關於式(XI)之隱形脂質的組合物及用途。亦提供製造該等化合物、組合物及調配物之方法,以及該等化合物、組合物及調配物將生物活性劑傳遞至細胞及/或組織中的方法及用途。