الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Hydroxyapatite based biomaterials have received great interest since the main constituent of inorganic mineral component in human bone. The goal of this study is to extract natural HAp from fine bone powder and its products will be discussed in four sections: (1) Extraction of fine bone powder, (2) synthesis of agglomerated Nano-sized Hap powder, (3) characterization of bone powder and its products, (4) in vivo testing of extracted Hap powder. HAp powder was extracted using hydrothermal treatment and synthetic HAp powder was prepared using a co-precipitation method. The initial characterization of all samples was performed using x- ray diffraction technique, infrared spectroscopy . Scanning electron microscopy images were obtained for topological studies and transmission electron microscopy images to study the particle size and morphology. Making use of the inductive coupling plasma( ICP) method the content of trace element was determined. In vivo tests of Hap powder were performed in rabbit femoral defects for 6 weeks. On other hand the experimental part of this study is to prepare and develop sustained drug delivery system for carrying poorly soluble and low-dose drugs. The drug delivery system combines three components: hydroxyapatite (HAp), sodium silicate and ascorbic acid, which blended together to form solid tablets exhibiting optimal characteristics as drug carriers. Both synthetic HAp (s-HAp) and extracted natural HAp (n-HAp) have been used as sources of HAp due to their optimal biological properties and adsorption ability. Aqueous drug solutions of atenolol, an antihypertensive drug, have been used as a model drug to study the drug release actions of HAp composites. drug to investigate the drug release behaviour from HAp composites. The properties of s-HAp, n-HAp powders and HAp composites tablets were characterized by using Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD),Transmission electron microscopy (TEM),and UV- spectrophotometer was used to study drug release from HAP tablets. The results indicated that both s-HAp and n-HAp were pure powders and exhibited agglomerated microstructures with grain sizes of less than 100 μm. The HAp composite tablets exhibited a dense structure, excellent compressive strength and excellent in vitro release behavior of atenolol. The results show that HAp powders and their composite tablets can be promised as economic raw materials and low-dose drug carriers.