synthesis of nano hydroxyapatite: application in drug delivery of sulfasalazine

in this work we synthesized nano hydroxyapatite (hap)  by sol-gel method, then we functionalized hydroxyapatite nanoparticle by use of  3-aminopropyl trimethoxysilane (aptms) , to improve the loading and control release of sulfasalazine drug bonded to aptms. the drug release patterns from sulfasalazine loaded hap nanoparticles at ph value 8 for 6h, sulfasalazine loaded functionalized hap nanoparticles (sulfasalazine loaded hap-aptms) at ph value 8 as in the intestine for 48h. moreover, the functionalized hap showed relatively slower release rate of sulfasalazine compare with non functionalized hap. because the strong ionic interaction between nh2 group in sulfasalazine in hap-aptms. on other side, the functionalized hap loaded more drug than pure hap. the synthesized nanoparticles and functionalized hap characterized by scanning electron microscopy (sem), x-ray diffraction (xrd), fourier transform infrared (ft-ir) and  uv/vis analysis techniques. then the obtained material was studied in the simulated body fluid (sbf) to this investigated storage and release properties.