Pharmacokinetic behavior of cyclosporin A in rabbits by oral administration of lecithin vesicle and Sandimmun Neoral.

The present study was undertaken to investigate the incorporation of lipophilic polypeptide, cyclosporin A (CsA) into lecithin vesicular system and to compare its pharmacokinetics behavior with Sandimmun Neoral (CsA-NEO). Lecithin vesicles of cyclosporin A (CsA-VES) were prepared by the rotary evaporation method, treated further with sonication. Studies were carried out to characterize the vesicles on physical properties, content, entrapment efficiency, particle size, polydispersity and Zeta potential. Pharmacokinetic behaviors were studied in rabbits at dose of 30 mg/kg. Results showed CyA vesicles were spherical particles, with content of 3.137+/-0.060% mg/ml, entrapment efficiency of 98.91+/-0.80%, particle size of 63.89+/-4.75 nm, polydispersity of 43.2+/-6.1% and Zeta potential of -13 mV. The best model fitting experimental data was a two-compartment open model with first-order kinetics. The relative bioavailability of CsA-VES versus CsA-NEO was 105+/-21% (n=6) and statistical analysis demonstrated both preparations were bioequivalent. In conclusion, lecithin vesicles are promising carriers in the oral delivery of CsA, considering their absorption enhancement effect and low-toxic property.