Investigation of the effects of delivery system properties on drug delivery

Drug delivery systems have been attracted a great deal of attention because of targeted drug delivery in the field of pharmaceutics. Hydrogels are suitable candidates as drug delivery systems due to their porous architecture. Also, hydrogels are used in control drug release because of their ability to change the gel structure in response to environmental situation. Hydrogels can be released in a controlled manner since they can swell without being dissolved. The important physicochemical and biological characteristics of hydrogels, along with their huge diversity, have led to desirable attention to these polymeric materials as candidate for delivery systems of therapeutic agents. Their high water content, biocompatibility and flexibility give rise to potential applications in topical, transdermal, sustained drug delivery and medicine. Some of them exhibit good properties, such as elasticity and mechanical strength, and, due to their water absorption ability, they can be applied in different areas for controlled release of drugs and proteins. Ionic gelation has been used largely preperation of sodium alginate based hydrogels. Photopolymerization has been used largely in the preparation of photopolymerized materials. Alzheimer's disease is an irreversible, progressive brain disorder which leads to deterioration of intellectual and social functions, memory loss, personality changes and inability for self-care. AD is the fourth leading cause of death in developed countries. In this study; an Alzheimer drug donepezil hydrochloride (DH) which was encapsulated in to sodium alginate (NaAlg) hydrogels were modified with α-cellulose, gelatine, clinoptilolite, modified clinoptilolite and 4-acryloyl morpholine via ionic gelation. PEG-DA and HEMA-based hydrogels were prepared in the presence of a photo-initiators (Irg 184, Irg 651, Irg 2959) and cross-linking agent (ethylene glycol dimethacrylate). Donepezil hydrochloride (API for treatment of Alzhemier disease) which was encapsulated in to PEG-DA and HEMA hydrogels were combined with rutile TiO2 or HAp in via photopolymerization. Fourier Transform Infrared (FT-IR) spectroscopy and digital microscope, 13C NMR and rheometer were used to characterize the hydrogels. Swelling, release analyses were done. Release kinetic models were investigated. In conclusion, this kind of hydrogels can appropriate for use in the controlled release of drugs.