PubMed1993
Liposomes are microscopic structures consisting of one or more lipid bilayers enclosing a definite aqueous space. They are widely used as a drug carrier and for the delivery of drugs through membranes. Drugs can be encapsulated into the inner water phase or lipidic wall, depending on their own hydro- or lipophilicity. The characteristics of the vesicles is fusion with cells and natural endocytosis uptake. We applied the properties of liposomes to overcome the poor gastro-intestinal (GI) absorption of griseofulvin and compared results with the traditional dosage form. In this experiment, the maximum plasma concentration obtained from griseofulvin liposomes was about 2.6 times than that from griseofulvin suspension. We used the lipids to prepare liposomes that consisted of phosphatidycholine, cholesterol, and dicetylphosphate in the molar ratio, 1:1.6:0.2, which is similar to the membrane composition of red blood cells. We examined some factors affecting the encapsulation ratin (E.R.%) and physicochemical properties of liposomes. When the lipid-to-griseofulvin weight ratio approached 38:1, the encapsulation ratio reached 94%. The different lipid/aqueous ratio (19/1 48/1 96/1) appeared to have little effect on E.R. value. The stability of griseofulvin liposomes in terms of leakage of griseofulvin was negligible over a period of 18 days at 4 degrees C. The sedimentation of vesicles bearing negative charges exhibited the best flocculation state. The plasma level-time profile of griseofulvin obtained from ingestion of liposomal dosage form showed itself to be significantly higher (P<0.01) Cmax, AUC, Ka, and t1/2 than that from suspension.