Poly(phthaloyl-l-lysine)-coated multilamellar vesicles for controlled drug delivery: in vitro and in vivo performance evaluation

Nonionic surfactant vesicles were prepared using Span 60, cholesterol and dicetyl phosphate. The prepared multilamellar vesicles (MLVs) were coated by interfacial polymerization technique using p-phthaloyl dichloride and l-lysine. The formation of the polymeric coat was confirmed by optical microscopic and transmission electron microscopic studies. The prepared, plain and polymer-coated MLVs were studied for their size, shape, encapsulation efficiency, in vitro release profile and effect of osmotic shock on vesicle. The results observed showed that the polymer-coated MLVs were stable under various osmotic conditions. In vivo studies were carried out on albino rats. The half-life and area under curve were found to be high in the case of polymer-coated MLVs as compared to plain MLVs and plain drug solution. In vivo studies using inflammed rat model also indicated that the polymer-coated MLVs were more stable and could release the drug in a controlled fashion as compared to plain MLVs.