| In recent years, much attention has focused on mucous membrane drug delivery system due to many advantages over the other routes of administration. The mucous membrane drug delivery system can protect drugs from being destroyed by enzymes in the stomach and intestines and it can also reduce the side-effect of the drugs. It is very necessary to develop novel mucous membrane delivery system. In this study, the lecithin-based vesicles for buccal delivery and ophthalmic gels for ophthalmic delivery were investigated. The main results are as follow.(1) Three methods were investigated for the construction of the soybean lecithin-based vesicles. The vesicles were characterized by photon correlation spectrometry (PCS) and the stability of the vesicles was studied. The transmission electron microscopy (TEM) showed that soybean lecithin-based vesicles had a spherical shape, and the particle size about 100 nm. The soybean lecithin-based vesicles have good stability in 2～6℃and the average particle size accorded with that from PCS.(2) The insulin-loaded vesicles for buccal delivery were prepared. The average particle size of insulin-loaded vesicle is 121.9nm, which is higher than that of the non-loaded vesicle. The permeation flux of insulin of vesicles and the control were 0.0024 IU·mL-1·min-1 and 0.008 IU·mL-1·min-1, respectively. The accumulative amount of insulin from vesicles at 3h was (0.436±0.010) IU·mL-1, which was 2.46 times than that from the control solution.(3) The pilocarpine-loaded gels containing HPMC and sodium hyaluronate for ophthalmic delivery were prepared. The penetration test showed that the penetration flux of pilocarpine of gel and the control solution were 2.197μg·mL-1·min-1 and 3.390μg·mL-1·min-1. The accumulative amount of gel at 5h was 550.83μg·mL-1. The pilocarpine gel showed a slower release effect than the solution. The stimulation test was performed and no stimulative effect of gel on the eye of rabbits was found.(4) The in situ poloxamer 407-based gels were prepared. The relationship between temperature and the concentration of polaxamer 407 was discovered. The phase transfer termperature of gel with 18 % polaxamer 407 was 23.6℃. The in vitro release experiment showed that the dissolution amount of 17 %, 18 %, 19 % and 20 % poloxamer solutions were 1.996, 1.704, 1.445 and 1.007 g, respectively. the drug release velocity of those were 0.150, 0.142, 0.131 and 0.098 mg·mL-1·min-1. The dissolution effect was relative to the concentration of polaxamer 407. The high concentration of poloxamer 407 could lead to slower dissolution of the gel. |
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