Characterization and evaluation of porous hydroxyapatite synthesized by oil-in-water method as carrier of donepezil for the preventive of Alzheimer's disease by controlled release

Alzheimer's disease (AD) is the most common cause of dementia. Patients are generally to forget taking pills because of memory loss or to skip medication due to side effects; that might stop the medication and affect the results of the treatment. In this study, we combine donepezil with hydroxyapatite (HAP-DPZ) to deliver by intramuscular (IM) injection, which may prevent from patient to skip the daily medication and keep the medicine at a constant level in the blood to achieve a constant release. HAP particles synthesized by using the new oil-in-water method, the XRD pattern, and the FTIR spectrum were proved the synthesized of HAP. SEM and DLS showed the particle size of synthesized HAP-DPZ was in the range of 0.9-3 mu m, which all in the optimal range for cellular uptake. In the drug release profile, DPZ could be released from HAP-DPZ by endosome/lysosome complex to achieve control releasing. In vitro study, there was no cytotoxicity found in HAP-DPZ. In the animal study, only one injection of HAP-DPZ administration, rats revealed well-focused searching strategies with the longest swimming time and most finding times in the quadrant where the platform was initially after three weeks.