Oral bioavailability studies of niosomal formulations of Cyclosporine A in albino rabbits.

Cyclosporine A (CsA) is an immunosuppressant agent. Two niosomal formulations of CsA, FTS and FSB were formulated. Both formulations were studied in terms of size, polydispersity index (PDI), morphology and entrapment efficacy etc. Niosomal formulations FTS and FSB and plain aqueous dispersion were given to three assemblies of Albino rabbits (n=8 per group). CsA levels in plasma were determined at appropriate time intervals and pharmacokinetic parameters were evaluated. The percentage entrapment efficiencies of FTS and FSB were found to be 77.29 and 89.31% for respectively. Transmission electron microscopy results indicated spherical nature of niosomes. In vivo studies demonstrated that the value of Cmax for the FSB formulation was 1968.419 ng/ml and it was 1498.951 ng/ml and 1073.87 ng/ml for FTS and aqueous dispersion of CsA (control) respectively. It was found that both niosomal formulation FTS & FSB presented significantly high (p<0.05) Cmax, AUC0-t, MRT 0-inf and half-life (t1/2) as associated to plain drug dispersion. However niosomal formulation FSB exhibited better in-vivo performance as compared to FTS. It was established that CsA can be successfully entrapped in niosomes. So niosomes are promising vehicle for CsA oral delivery.