新型防龋制剂氟化钠明胶微球的释氟特性研究

Fluoride-releasing property of Sodium Fluoride Gelatin Microspheres as a new type of anti-caries agent

目的为提高氟防龋的效果,制备新型防龋制剂—氟化钠明胶微球并观察其体外释药和在家兔体内的缓释效果,探讨其作为新型防龋制剂的应用前景。方法以氟离子选择性电极法测定氟含量,采用动态透析法分别观察微球制剂在生理盐水、pH6.8的人工唾液、pH4.0的人工唾液中的缓释规律,数据以TableCurve2D软件进行曲线拟合;另取家兔6只,分为2组,分别在牙面给予同等含氟量的微球剂和溶液剂,定时取唾液测定氟含量,1周后2组交换重复上述实验。结果在生理盐水中NaF-GMS的体外释放符合一级动力学方程ln(85.49-P)=-0.028t+4.448,T1/2为24.75min,对照组溶液剂T1/2为5.05min;NaF-GMS在pH4.0的人工唾液中释药规律符合方程ln(87.88-P)=-0.033t+4.004,T1/2为21.0min;在pH6.8的人工唾液中释药方程为ln(88.06-P)=-0.031t+3.986,T1/2为22.64min。家兔体内释氟实验表明微球组在90min内唾液氟含量都较基线水平有显著提高(t=4.267,P<0.05);而溶液组唾液氟含量高于基线的时间为(27±5)min。结论氟化钠明胶微球在生理盐水和人工唾液中都具有缓释能力,在pH4.0条件下释氟速度加快,有利于酸攻击时提供更多的氟离子促进釉质再矿化;动物试验证明它可以显著延长氟在口内的滞留时间,有可能成为新型防龋制剂。

Aim To observe the anti caries effect of sodium fluoride gelatin microspheres in encapsulating sodium fluoride in vitro and vivo of the rabbits and investigate its application prospect as new type of fluoride agent. Methods The in vitro fluoride releasing profiles of NaF GMS in saline and artificial saliva (pH4.0, pH6.8 respectively), as well as Rabbits' salivary fluoride concentrations before and after topical administration of NaF GMS and NaF solutions were tested using a fluoride electrode at different times. Six rabbits were divided into two groups equally and treated with microspheres and solutions of equal amount of fluorine respectively.The concentration of fluorine was measured.Results The study showed that fluoride releasing kinetics in vitro fitted to first order equations.In saline,the equation was ln(85.49 P)=- 0.028t+ 4.448,T1/2 was 24.75 min,while the T1/2 of NaF solution was 5.05 min. It could be concluded from this point that the NaF GMS had a slow release property. Moreover, data in artificial saliva of pH4.0 and pH6.8 following the equations of ln(87.88- P)=- 0.033t+ 4.004,(T1/2=21.0 min) and ln(88.06- P)=- 0.031t+ 3.986, (T1/2=22.64 min) respectively.Rabbits' salivary fluoride concentration were higher than base level at least in 90min in NaF GMS group( t=4.267,P< 0.05) ,while in NaF solution group that was (27± 5)min. Conclusion The experiment indicates that NaF GMS has slow release property in vitro and their fluoride release rate increases in pH4.0 artificial saliva.Fluoride gelatin microspheres may be an efficient topical fluoride agent.Experiments conducted in rabbits' oral cavity using NaF GMS and NaF solution as control reveal that NaF GMS maintains oral fluoride retention longer than NaF solution dose. NaF GMS is anticipated to be a new type of anti caries fluoride agent.<P>