الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
During last decades term nanotechnology has evolved in the medical field that produced a field called “nanomedicine” that makes a use of the massive decrease in particular size accompanied with enormous increase in the surface area. Different nanodrug delivery systems (NDDSs) have been designed (liposomes, niosomes, polymeric and solid lipid nanoparticles , nanocapsules and nanocrystals) to improve the pharmaceutical quality (safety and efficacy) of drugs through enhancing of their solubility, bioavailability, pharmacological activity stability and lowering the side effects by targeting ,enhancing tissue distribution and protection from physical and chemical degradation.
Surface coating of the (NDDSs) also considered one of the new strategies for enhancing drug pharmaceutical quality through improvement of drug absorption and lowering side effect due to degradation products of the drug. Chitosan (Cs) is biodegradable cationic mucoadhesive polymer that may be used as a coat for NDDS. Cs was reported to enhance drug permeation, mucoadhesion and provide a physical shield protecting drug against physical and chemical instability.
Diacerein is a drug used for the treatment of osteoarthritis by inhibition the synthesis and activity of interleukin 1-β (inflammatory mediator in osteoarthritis), it suffers from low oral bioavailability (35% - 56%) due to low water solubility also it has a side effect of diarrhea that is attributed to the hydrolysis of the unabsorbed portion of diacerein into rhein that has local stimulatory effect on the intestinal motility.
This thesis focused on enhancing diacerein pharmaceutical quality through the improvement of its oral bioavailability by particle size reduction and also lowering its side effect by decreasing the unabsorbed portion of the drug and also by protecting it against hydrolysis by chitosan coating.
Chapter one
Diacerein and chitosan coated diacerein nanosuspensions: preparation, optimization and in-vitro characterization.
The current work adopted the development and in-vitro evaluation of DCN nanosuspension and surface coated DCN nanosuspension using cationic mucoadhesive polymer (chitosan). First, DCN-NS was prepared using sonoprecipitation method after testing different nanoprecipitation methods then different method parameters were tested to choose the optimum ones. Stabilizers of different natures (HPMC-E15 , PVP K-25 , PXMR-188 and SDS ) and ratios (4:1, 2:1 and 1:1 w/w, DCN to stabilizer) were studied and PVP k-25 showed the best results at ratio of (4:1).