Maitani Y, Hazama M, Tojo Y, Shimoda N, Nagai T
Department of Pharmaceutics, Hoshi University, Tokyo, Japan.
J Pharm Sci. 1996 Apr;85(4):440-5. doi: 10.1021/js950477m.
Intestinal absorption of recombinant human erythropoietin (Epo) encapsulated in liposomes (Epo/liposomes) was examined by measuring the pharmacological effects of Epo after oral administration in rats. Circulating reticulocyte counts after oral administration of Epo/liposomes showed a profile different from that after intravenous administration. Epo/liposomes 0.1 micron in diameter were absorbed more effectively than those 0.2 micron in diameter. In the 0.1 micron Epo/liposomes composed of dipalmitoylphosphatidylcholine (DPPC) and soybean-derived sterols (SS), cholesterol (Ch), or soybean-derived sterylglucosides (SG), DPPC/SS (in molar ratio 7/2) and DPPC/Ch (7/2) showed higher efficiency in intestinal absorption than DPPC/Ch (7/4) and DPPC/SG (7/2) at a low dose by the sysmex method. Pharmacological availabilities for oral administration of Epo/liposomes were 0.74-31% and 3.3-30% as evaluated by circulating reticulocyte counts and percentage circulating reticulocytes of erythrocytes, respectively, in comparison to those for intravenous administration of the same dose.
通过测量大鼠口服重组人促红细胞生成素（Epo）脂质体（Epo/脂质体）后的药理作用，研究其肠道吸收情况。口服Epo/脂质体后循环网织红细胞计数呈现出与静脉注射后不同的特征。直径0.1微米的Epo/脂质体比直径0.2微米的吸收更有效。在由二棕榈酰磷脂酰胆碱（DPPC）和大豆衍生甾醇（SS）、胆固醇（Ch）或大豆衍生甾糖苷（SG）组成的0.1微米Epo/脂质体中，通过sysmex方法，在低剂量下，DPPC/SS（摩尔比7/2）和DPPC/Ch（7/2）的肠道吸收效率高于DPPC/Ch（7/4）和DPPC/SG（7/2）。与相同剂量静脉注射相比，口服Epo/脂质体的药理利用率分别通过循环网织红细胞计数和红细胞循环网织红细胞百分比评估为0.74 - 31%和3.3 - 30%。
