No abstract

Liposomes are man-made organelles composed of bimolecular lipid layers enclosing aqueous compartments. Dexamethasone Sodium Phosphate (DSP) was encapsulated in MLV liposomes and served as the test solution. DSP in solution served as control. Both were labeled with 99mTc. The rats were divided into three groups: typical application group, intramucosal injection and control group. Oral mucosal ulcers were produced by silver nitrate and was monofocal. Rats were killed at three and 24 h, respectively, after application. Ulcerated mucosa, intact adjacent mucosa and distant mucosa were excised. Biodistribution was determined by radiotracer technique in the three mucosal parts as well as in the blood, liver, spleen and brain. Liposomes increase local and decrease systemic drug concentration. Another finding was that liposomes localize the drug in the ulcerated area. In conclusion, liposomes may be useful in the treatment of oral ulcers.

Dexamethasone Sodium Phosphate (DSP) is a water soluble anti-inflammatory steroid commonly used in the therapy of serious types of ophthalmic inflammation. It has been demonstrated that unless the corneal epithelium is damaged, DSP is poorly absorbed by the cornea (Kupferman et al. 1974). Thus, it is doubtful whether such a drug would cure inflammation of the anterior segments. For this purpose, several liposomal DSP formulations containing phospholipid: charge inducer: cholesterol in molar ratios of 10:1:4 were investigated. Both gel state (PL 90H: SA: Cho1) and liquid state (PL 100: SA: Cho1) liposomes were prepared. For the preparation of liposomes, the film method followed by bath sonication was used. Liposomes were labelled with (99m)-Tc and administered intra-ocularly to New Zealand white rabbits weighing 2.5-3 kg for in vivo experiments. The biodistribution of the labelled liposomes were determined. For this purpose, eye segments (such as cornea, lens, iris, ciliar body, vitreous, aqueous humor, conjuctiva and sclera) and RES organs (such as liver, pancreas, spleen) were removed at fixed time intervals. In the present study, the efficiency of liposomes for the delivery of water-soluble drugs was evaluated in rabbit eyes using DSP as a model drug in different liposomal formulations.

No abstract