Reference

Effect of chondroitin sulfate ion and calcium ion on the dispersion of hydroxyapatite

Effect of chondroitin sulfate ion and calcium ion on the dispersion of hydroxyapatite. Shimabayashi, Saburo; Sumiya, Shigeyuki; Nakagaki, Masayuki (Fac. Pharm. Sci., Kyoto Univ., Kyoto 606, Japan). Yakugaku Zasshi, 104(10), 1024-9 (Japanese) 1984. CODEN: YKKZAJ. ISSN: 0031-6903. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) Section cross-reference(s): 1 Optical d. (OD), as an index for the suspension stability of hydroxyapatite (HAP) [1306-06-5] (5 g/dL), was measured at 550 nm in an aq. soln. of CaCl2 mixed with Na chondroitin 6-sulfate (Na2Chs) [12678-07-8]. The contour lines for OD with respect to concns. of CaCl2 and Na2Chs were obtained. The suspension stability of HAP decreases with an increase in concn. of CaCl2, but increases with an increase in concn. of Na2Chs. HAP suspension is stabilized mainly by virtue of a steric hindrance effect and inter-particle electrostatic repulsion effect of neg. charged segments of adsorbed Chs, even though ionic strength is high and the net charge of HAP particles becomes pos. (i.e., the amt. of adsorbed Ca2+ is larger than that of adsorbed Chs).