呋喃妥因片剂的体外溶出度对体内生物利用度的影响

Relationship between bioavailability in vivo and dissolution in vitro of nitrofurantoin tablets

目的 为了说明以溶出度作为控制呋喃妥因片质量的必要性 ,考察了其体内吸收和体外溶出度。方法 参照USP2 4版规定条件 ,检测了 4个厂家的呋喃妥因片的溶出速率。将具有显著溶出差异的两种片剂口服给药后 ,采用高效液相色谱法测定人体尿样浓度 ,进行生物利用度评价。结果 两种片剂在 2h内体外溶出度分别为 89%和 15 % ;在健康志愿者体内尿中原形药物排泄率分别为 10 .77% ,1.5 4 %。体外溶出和体内吸收有显著差异。结论 此体外溶出方法可以作为评价呋喃妥因片生物利用度的参考标准。

OBJECTIVE: To study the correlation between the absorption in vitro and the dissolution in vitro of nitrofurantoin (NF) tablets, in order to illustrate the necessity of checking dissolution as a method of quality control of nitrofuran tablets. METHODS: The dissolution rate of four brands of marketed nitrofuran tablets were checked according to the USP24th edition. The two brands with great difference of dissolution rate were administered in 10 healthy male volunteers. The NF concentrations in urine were determined by HPLC to evaluate the bioavailability. RESULTS: Two brands with drug dissolution of 89% and 15% in 2 hours excreted unchanged nitrofuran in urine were 10.77% and 1.54%, respectively. The correlation between dissolution in vitro and absorption in vivo was significant. CONCLUSION: The results showed the dissolution in vitro can be used as a reference criteria for primarily evaluating the bioavailability of nitrofurantion tablets.