Ocular drug delivery system for astragaloside Ⅳ liposome in situ gel
Objective To prepare astragaloside Ⅳ(ASⅣ)liposome in situ gel(ASⅣ lips gel),characterize the formula and evaluate the cytology of ASⅣ lips gel,and determine the potential application of AS Ⅳ lips gel in ocular drug delivery system.Methods Astragaloside-Ⅳ liposome(AS Ⅳlip)was prepared by ethanol injection.ASⅣ lips formula and preparation process were optimizaed with encapsulation efficiency as the evaluation index.ASⅣ lips with the best formula and process were charactered.Chitosan(CS)and sodium glycerophosphate(GP)were used as the gel matrix,CS/GP gel was prepared by physical crosslinking,and the properties of CS/GP gel were characterized.The AS Ⅳ lips were loaded into CS/GP gel to obtain ASⅣ lips gel,the stability,in vitro release,cytotoxicity and cell uptake of ASⅣ lips gel were determined.Results The average particle size of optimized ASⅣ lips was(75.09±0.65)nm,which was consistent with the particle size by transmission electron microscopy and the distribution was uniform.The encapsulation efficiency of AS Ⅳ lips prepared by the optimal formula and process reached 71.68％,indicating good encapsulation efficiency for ASⅣ.The CS/GP gel was successfully prepared by infrared spectroscopy and X-ray diffraction.The CS/GP gel showed obvious three-dimensional network structure under scanning electron microscope,and the gelling time was 3 min at 35 ℃.ASⅣ lips gel showed no obvious change in the particle size for 7 consecutive days,suggesting good stability.The in vitro release showed that compared with ASⅣ eye drops,ASⅣ lips gel had an obvious sustained-release effect.The cytotoxicity showed that ASⅣ lips gel had low toxicity to human retinal pigment epithelial cells and good cell compatibility.Liposome in situ gel was more easily absorbed by human retinal pigment epithelial cells than did eye drops.Conclusion The prepared ASⅣ lips gel can spontaneously form gel at eye temperature and has a fair sustained-release effect.It is more easily taken up by human retinal pigment epithelial cells and indicating possible ocular drug delivery system.
NETL
NSTL
万方数据
