Preparation of Ethosomes and Deformable Liposomes Encapsulated with 5-Fluorouracil and Their Investigation of Permeability and Retention in Hypertrophic Scar

With the aim of comparing scar penetration efficiency and retention between ethosomes and deformable liposomes both encapsulated with 5-fluorouracil (5-FU), the 5-FU ethosomal suspensions (5-FU ES, 81.74 +/- 9.37 nm) and the 5-FU Deformable Liposomal Suspensions (5-FU DS, 73.7 +/- 9.45 nm) were prepared respectively by Touitou method and Cevc method, their sizes were determined by Particle Sizer System (PSS), and their entrapment Efficiency (EE) was detected by ultracentrifugation and microcolumn centrifugation. Their transdermal delivery experiments were done in hypertrophic scars in vitro. The permeated amount of 5-FU and retention contents of 5-FU were both calculated by High Performance Liquid Chromatography (HPLC). Fluorescence intensities of ES and DS labeled with Rodanmin 6GO (Rho) were measured by Laser Scanning Microscopy (LSM). The control groups such as the 5-FU and empty ethosomal vesicles (5-FU + EEV), the 5-FU and empty deformable liposomal vesicles (5-FU + EDV) and 5-FU PBS Solution (5-FU Sol) were set up. Results showed that, prepared 5-FU ES was 81.74 +/- 9.37 nm in size, 5-FU DS was 73.7 +/- 9.45 nm, EE of 5-FU ES was 10.95%, EE of 5-FU DS was 15.05%. Within 24 hours, in the group of 5-FU ES, the penetration amount of 5-FU in scar was 14.12 +/- 0.1 mu g/mL/cm(2), the retention contents of 5-FU was 10.74 +/- 1.17 mu g/cm(2), and the fluorescence intensity of Rho in hypertrophic scar tissues were 182 +/- 18.3; in the group of 5-FU DS: the penetration amount of 5-FU was 12.35 +/- 1.21 mu g/mL/cm(2); the retention contents of 5-FU was 17.48 +/- 0.82 mu g/cm(2), and the fluorescence intensity of Rho was 241.45 +/- 7.63; there existed statistical difference between penetration amount in the group of 5-FU ES and that in the group of 5-FU DS as well as control groups (P < 0.05, P < 0.01), the penetration amount in the group of ES is markedly higher than DS group or control groups. Conversely, the retention contents of 5-FU and the fluorescence intensity of Rho in DS group were higher than those in ES group and control groups (P < 0.05, P < 0.01). In conclusion, both ES and DS could deliver 5-FU into the hypertrophic scars effectively. ES has better permeability of 5-FU than DS, DS has higher entrapment efficiency of 5-FU, and more 5-FU deposition in hypertrophic scar than ES. We should select ES or DS encapsulated with 5-FU according to clinical demand for hypertrophic scar therapy.