| Summary: | 碩士 === 大同大學 === 生物工程學系(所) === 95 === The ursolic acid encapsulated by liposome and different penetration enhancer was used to evaluate the improving effects for the drug transdermal delivery. The formulations for liposome included phospholipids such as egg-york L-α-Phosphatidylcholine (EYPC), and dipalmitoylphosphatidylcholine (DPPC). The enhancer included surfactants like deoxycholic acid (DA), stearylamine (SA), and Sorbitan monooleate (Sp80). Besides, we also used olive oil and lard to prepare oil-suspension for ursolic acid. To measure the permeability coefficient of ursolic acid under different formulations, we used the Franz-type diffusion cell to perform the transdermal penetration test. Furthermore, fluorospectrometer analysis was designed to evaluate the penetration ability of liposome by a fluorescent probe. Comparing different surfactant incorporating DA and Span80 into liposome affected the lipid-bilayer arrangement and made liposome more penetrable. The permeability coefficient of transdermal delivery for the ursolic acid(3 mM) encapsulated by liposome (containing EYPC only) was 0.025 ±0.002 cm/hr, but the permeability coefficient of the ursolic acid unencapsulated by liposome was only 0.017 ±0.001 cm/hr. The result indicates that the encapsulation of liposome promotes the drug delivery. The transdermal permeability coefficient will increase along with the increasing concentration of encapsulated ursolic acid. As a result, the transdermal permeability coefficient for the liposome which included EYPC or DPPC (containing no surfactant) did not show the significant differences. By incorporating DA into liposome, the permeability coefficient will reach as high as 0.042 ±0.002 cm/hr. If we compare DA with SA, the permeability coefficient of ursolic acid in liposome of SA is only 0.022 ±0.002 cm/hr. Therefore, a better penetrability of liposome by the fluorescent probe also show a higher permeability coefficient of ursolic acid encapsulated by such liposome. The oil suspension of ursolic acid in DA and lard had the highest permeability coefficient of 0.049 ±0.002 cm/hr. Therefore, oil-suspension shows a better drug transdermal delivery than liposome.
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