Abstract
Purpose: Prognosis of dental implant therapy after placement is commonly dependent on the efficient bonding
of titanium implant and jaw bone. Simvastatin (SIM), which is a classic antihyperlipidemic drug, has been
remarkably attracted in dental region since it was reported that SIM has bone regeneration effect, and thus,
SIM has been expected as the compound to support dental implant therapy. In this study, we aimed for the
development of simvastatin-loaded gelatin/hydroxyapatite spherical granules (SIM/GE/HAP) using spheronizer
(Marumerizer) for efficient dental implant therapy.
Methods: Preparation of SIM/GE/HAP: SIM/GE/HAP was prepared using spheronizer for producing on a large
scale. Characterization of SIM/GE/HAP: The surface morphology of the SIM/GE/HAP was visualized using a
scanning electron microscope. In vitro drug release in phosphate buffered saline (PBS) or simulated body fluid
(SBF): The SIM/GE/HAP was determined by UV-VIS spectrometer. To understand the mechanism of SIM
release from the SIM/GE/HAP, the results of in vitro release profiles were fitted to a mathematical model.
The X-ray powder diffraction (XRD) profile of SIM/GE/HAP was measured by powder X-ray diffractometer to
evaluate the composition and crystallinity of the granules before and after in vitro release test.
Results: The SIM/GE/HAP in SBF exhibited sustainable release profile for 1 week. In contrast, the SIM/GE/
HAP in PBS released SIM approximately 60% within 1 week. These results mean that SIM/GE/HAP implanted
in the body can release SIM until the implant is attached with jaw bone. The XRD spectrum of SIM/GE/HAP
after the release test in SBF was characteristics of HAP. On the other hand, The XRD spectrum of SIM/GE/
HAP after the release test in PBS showed most parts of granule bulk did not transform into HAP.
Conclusion: The results showed that SIM/GE/HAP prepared using spheronizer could release SIM continuously
and has a potential to promote the local bone regeneration.
Keywords: Bone regeneration, Simvastatin, Hydroxy apatite, Drug delivery system, Controlled release
