ヒドロキシアパタイトに対する塩化セチルピリジニウムの吸着

概要

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Adsorption of cetylpyridinium chloride (CPC) to hydroxyapatite (HAP) was studied. The amount of adsorbed CPC increased and decreased with the amount of added NaOH, and added NaCl or CaCl_2,respectively. It was assumed that cetylpyridinium cation (CP^+) is adsorbed to negatively charged sites on HAP surface by electrostatic force. Adsorption of anions such as OH^- makes the number of adsorption sites for CP^+ increase on the surface of HAP (cooperative adsorption). But the effect of Cl^- anion, which may increase the amount of CP^+ adsorption, was assumed to be smaller than that of Na^+ cation, which decreases the amount of CP^+ adsorption, because NaCl, as a whole, inhibits CP^+ adsorption. Cations such as Na^+ and Ca^<2+> compete with CP^+ for the adsorption site charged negatively on HAP (competitive adsorption). The effect of Ca^<2+> was more remarkable than that of Na^+, since Ca^<2+> is one of the lattice ions of HAP crystal. As the affinity of Ca^<2+> to HAP is stronger than that of CP^+, the adsorption isotherm of Ca^<2+> became just one curve irrespective of concentration of CP^+ added. The fact mentioned above may be one of the reasons why hard tissues and renal calculi adsorb Ca^<2+> selectively from body fluid containing many kinds of organic and inorganic ions, and grow up in our human body.
公益社団法人日本薬学会の論文
1982-02-25