Control of bisphosphonate release using hydroxyapatite granules.
The efficacy of hydroxyapatite (HAp) as a carrier was investigated to establish a method of local administration of bisphosphonates (Bps), which has currently been administered systemically. HAp granules (300-500 microm in size) with different physicochemical features were prepared by altering the sintering temperature. To ascertain the physicochemical properties of the HAp granules, their crystallinity was assessed using X-ray diffraction, the surface morphology was examined under scanning electron microscopy, and the specific surface area and calcium dissolution were evaluated. Different Bps-HAp composites were subsequently prepared and the concentration of Bps released from these composites was measured. The influence of Bps-HAp composites on the rate of osteoclast survival was also evaluated. The results revealed that (1) HAp solubility depends on the sintering temperature; (2) The concentration of released Bps could be controlled by regulating the sintering temperature of HAp as a carrier; and (3) Bps released from Bps-HAp composites reduced the number of osteoclasts. These findings indicated that Bps-HAp composites could be locally administered as a drug delivery system to areas with bone resorption.
Department of Dental Materials Science, Oral Health Science Center, Tokyo Dental College, 1-2-2 Masago, Chiba 261-8502, Japan.
Hisashi
H
Seshima
Masao
M
Yoshinari
Shinji
S
Takemoto
Masayuki
M
Hattori
Eiji
E
Kawada
Takashi
T
Inoue
Yutaka
Y
Oda
D000818:Animals; D001862:Bone Resorption / Q000188:drug therapy* / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003460:Crystallization; D003692:Delayed-Action Preparations / Q000737:chemistry; D004164:Diphosphonates / Q000737:chemistry / Q000494:pharmacology*; D017886:Durapatite / Q000737:chemistry; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010010:Osteoclasts / Q000648:ultrastructure; D011817:Rabbits; D014961:X-Ray Diffraction
D003692:Delayed-Action Preparations; D004164:Diphosphonates; D017886:Durapatite