الفهرس 
General introductionOnly 14 pages are availabe for public view
 |  | from | 198 |  |  |
| | | from | 198 | | |
Abstract
Niosomes are colloidal nanocarriers which showed enhanced oral bioavailability of several drugs. They were expected to solve the troubles encountered by oral administration of candesartan cilexetil. The 23 DOE choose the formulation F7 as the optimized one with high entrapment efficiency percent, low particle size and low polydispersity index. Formulation F7 showed also acceptable zeta potential value. The optimized chitosan coated niosomal formulation showed reasonable particle size and zeta potential values. The drug-excipients compatibility study via FTIR and DSC, ensured the absence of interactions between the drug and the niosomal components as well as the drug entrapment within niosomes. Chitosan coated niosomes experienced higher mucoadhesion capability with mucin than that of uncoated ones. The niosomal excipients were biocompatible with Caco-2 cells and could protect these cells from the toxicity of the free drug. After oral administration of the niosomes with silicified microcrystalline cellulose, they showed augmented an absolute bioavailability of candesartan around 37% which was superior to the reported one in humans (15%). The enhanced absolute bioavailability certified the virtue of the miraculous molecules of glyceryl monooleate together with span 60. The pivotal role of chitosan in stimulating the drug absorption from chitosan coated niosomes, might be reflected by high absorption rate constant (ka) value, despite the lower mean residence time (MRT) value than that of uncoated ones.