الفهرس 
Part 1 : Formulation and evaluation of DSN-loaded polymeric nanoparticles
Chapter 1 : Formulation and optimization of DSN PLGA nanoparticlesOnly 14 pages are availabe for public view
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Abstract
Background: The goal of any drug delivery system is to provide a therapeutic amount of a drug to a proper site in the body, so that the desired drug concentration can be achieved promptly and then maintained. In recent years, considerable attention has been paid to the development of new drug delivery systems (DDSs). The nanosized DDS are among the dosage forms which were developed to achieve the intention of better patient compliance, modified drug release, delivery of drug at the site of action, more efficient administration of the drugs by various routes and hence better therapeutic effect. The objective of the present study was to prepare nanosized formulations using different polymers type. Objectives: Formulation, in vitro evaluation and in vivo study of diosmin nanoparticles and nizatidine nanofibers have been performed.Methods: PLGA was used to prepare nanoparticles of diosmin and coated with chitosan in purpose of improving its anti-ulcer activity and increasing in local drug concentration and prolonging residence time of the drug in GIT can increase the rate of absorption. Nanofibers seem to have gastro-retentive characteristics and a floating behavior. Nizatidine has a short biological half-life and a rapid clearance as it is susceptible to metabolism by colonic bacteria hence, chitosan/polyethylene oxide nanofibers loaded with nizatidine to improve ulcer treatment. Investigation of the anti-ulcer activity of both systems against ethanol-induced ulcer in rats was performed.Results: Formulae F5 and F14 were found to be the optimized uncoated and chitosan-coated nanoparticles, respectively with the highest entrapment and low particle size that containing 20 mg diosmin and 300 mg PLGA using methylene chloride as organic solvent. Chitosan-coated nanoparticles were more stable against size enlargement. Coating of PLGA nanoparticles with chitosan resulted in a highly potentiated anti-ulcer activity of diosmin. Gluteraldehyde crosslinked chitosan/polyethylene oxide nanofibers significantly potentiated the cytoprotective activity of nizatidine against ethanol-induced ulcer in rats due to the mucoadhesion of chitosan and floating property of the nanofibers.Conclusion: Finally, we concluded that, the optimized chitosan-coated nanoparticles (F14) could be considered as a promising delivery system for potentiated anti-ulcer activity of diosmin. The crosslinked CS/PEO electrospun NFs as a novel floating gastro mucoadhesive delivery system were found to be a good drug delivery system for drugs that have short half-life, rapid clearance and susceptible to metabolism by colonic bacteria. These nanofibers increase local delivery of nizatidine in the stomach for a long time which in turn can potentiate the bioavailability.