复合磷酸钙颗粒溶解性能测试研究

The study on dissolution testing of Calcium phosphate composite particles

目的研究复合磷酸钙颗粒(HA∶TCP=3∶7)在TRIS缓冲溶液中的体外溶解特性。方法配制一系列浓度逐级递增的Ca^(2+)标准溶液,绘制Ca^(2+)离子溶液的工作曲线。将复合磷酸钙颗粒(HA∶TCP=3∶7)置于pH值为7.4的TRIS缓冲溶液中浸泡,每小时取样一次(初始阶段每3分钟取样一次),用高速离心技术提取上层清液,采用电感耦合等离子体质谱法测定各时间点提取液的Ca^(2+)浓度,绘制Ca^(2+)浓度对浸泡时间的溶解曲线。结果 Ca^(2+)离子溶液的工作曲线的线性方程为y=4043.9x+23783,相关系数R为0.9999,方法检出限为0.0063 g/m L,定量限为0.021 g/mL。浸泡后最初的0.5 h以内,Ca^(2+)浓度随时间延长急剧升高,0.5 h处有明显转折,0.5 h至20 h,Ca^(2+)浓度仍随时间增加而升高,但是增加的速率较前0.5 h明显下降,20 h以后溶解达到基本平衡。复合磷酸钙颗粒的溶解过程分为3个阶段,首先是Ca^(2+)离子浓度快速升高的溶解过程,第二阶段是Ca^(2+)离子溶解与HA或Ca HPO_4·2H_2O沉积的竞争过程,第三阶段是Ca^(2+)离子浓度不再继续增加的稳定过程。结论复合磷酸钙颗粒(HA∶TCP=3∶7)在TRIS缓冲溶液中的溶解具有一定的规律性,24 h后溶出的Ca^(2+)离子浓度在1200 g/L左右。

Objective To study the dissolution characteristics of calcium phosphate composite particles （HA ： TCP=3 ： 7） in TRIS buffer solution. Methods A series of standard Ca2＋solutions with increasing concentration are prepared, and the working curve of Ca2＋ ion solution was drawn. The composite calcium phosphate particles （HA ： TCP=3 ： 7） in the pH value for 7.4 TRIS buffer solution, sampling once per hour （initial samples were collected every 3 min）, extracted from the supernatant by high speed centrifugation, measured at each time point of the concentration of Ca2＋ extraction liquid by inductively coupled plasma mass spectrometry. The dissolution curve of Ca2＋ concentration on soaking time was drawn. Results （1） The linear equation of the working curve of Ca2＋ ionic solution is y=4043.gx＋23783, and the correlation coefficient R is 0.9999. The detection limit is 0.0063 μg/mL, and the quantitative limit is 0.021 lag/mL. （2） After the initial immersion within 0.5 h, the concentration of Ca2＋ increased with time dramatically, marked a turning point at 0.5 h, From 0.5 h to 2 h, the concentration of Ca：＋ ion increased with time, but the rate of increase decreased obviously compared with the first 0.5 h. After 20 h, the dissolution reached the basic balance. （3） The dissolution process of calcium phosphate composite particles can be divided into 3 stages, the first is the dissolution process of Ca2＋ ion concentration increased rapidly, the second stage is the competition process of Ca2＋ dissolution with HA or CaHPO4 · 2H2O deposition, the third stage is the stable process of Ca2＋ ion concentration will no longer increase. Conclusion The dissolution of composite calcium phosphate particles （HA ： TCP=3 ： 7） in TRIS buffer solution has a certain regularity, and the concentration of Ca2＋ ions dissolved in 24h is about 1200 μg/L.