表皮生長因子之所以利用微脂粒包覆，其目的是為了保護其活性。本實驗進行生長因子在不同的配方中的活性安定性評估，包括了O/W型乳液、W/O型乳液和不同微脂粒配方等。我們選用三種磷脂質：LS-60HR、NC-20、NC-21製備微脂粒，其中只有NC-20是未氫化的磷脂質。結果顯示，這些微脂粒經過100 nm濾膜後的粒徑大約在110~150 nm，而NC-20的粒徑較氫化脂質LS-60HR和NC-21的粒徑小。而在包埋率方面，經擠壓器處理的微脂粒包埋率在80%以上，高於未經處理微脂粒的包埋率約60﹪左右。在儲存穩定性的評估，在45℃儲存環境下，O/W型和W/O型乳液中的生長因子活性在第10 天只剩原來的10﹪，而微脂粒劑型在第30天其活性仍為維持在50﹪以上，可見微脂粒確實有保護生長因子活性的功效。 Epidermal Growth factor (EGF) was encapsulated into liposome in order to protect it from the degradation. In this study, we examined the stability of EGF in different formulation including O/W lotion, W/O lotion and liposomes. Three phospholipids including LS-60HR, NC-20, NC-21 were employed for the preparation of liposome, in which only NC-20 is a non-hydrogenated lecithin. The results showed that the diameters of liposomes were around 110~150 nm. The diameter of NC-20 was smaller than that of hydrogenated lecithin LS-60HR and NC-21. The encapsulation efficiency of the EGF liposome with and/or without extrusion through polycarbonate filter were more than 80% and about 60% respectively. For the stability evaluation, the EGF activity in both O/W lotion and W/O lotion decreased to only 10% at 45℃ after ten-days, but these samples if encapsulated into liposomes could keep above 50% of activity at 45℃ after thirty-days. These results indicate that these liposomes effectively retains the activity of EGF.
