Otsuka M, Matsuda Y, Hsu J, Fox J L, Higuchi W I
Department of Pharmaceutical Technology, Kobe Pharmaceutical University, Japan.
Biomed Mater Eng. 1994;4(5):357-62.
The effect of environmental conditions on the crystalline transformation of metastable calcium phosphates during grinding was investigated using X-ray diffractometry and fourier transformed infrared spectroscopy. A mixture of CoA and dicalcium phosphate anhydrate (DCPA, CaHPO4) did not transform after grinding in air. On the other hand, CaO and dicalcium phosphate dihydrate (DCPD, CaHPO4 2H2O) were converted into a noncrystalline solid. Mixtures of DCPD and Ca(OH)2 transformed into low-crystallinity hydroxyapatite after grinding in air. When ground under N2, a mixture of Ca(OH)2 and DCPD did not transform into hydroxyapatite, whereas that of DCPD: Ca(OH)2: CaCO3 = 1:0.8: 0.2 did. The results of X-ray diffraction of FT-IR spectra suggested that the presence of carbon dioxide in the grinding system was necessary for transformation from metastable calcium phosphates to hydroxyapatite.
利用X射线衍射法和傅里叶变换红外光谱法研究了环境条件对研磨过程中亚稳磷酸钙晶体转变的影响。辅酶A（CoA）和无水磷酸二钙（DCPA，CaHPO4）的混合物在空气中研磨后没有发生转变。另一方面，氧化钙（CaO）和二水磷酸二钙（DCPD，CaHPO4·2H2O）则转变为非晶态固体。DCPD和氢氧化钙（Ca(OH)2）的混合物在空气中研磨后转变为低结晶度的羟基磷灰石。在氮气（N2）气氛下研磨时，Ca(OH)2和DCPD的混合物没有转变为羟基磷灰石，而DCPD:Ca(OH)2:CaCO3 = 1:0.8:0.2的混合物则发生了转变。X射线衍射和傅里叶变换红外光谱的结果表明，研磨体系中二氧化碳的存在是亚稳磷酸钙转变为羟基磷灰石所必需的。
