等温微量热技术比较原研和仿制头孢曲松钠体外抑菌效果

Comparison of anti-bacterial activity of original and generic ceftriaxone based on isothermal microcalorimetry

目的开发一种基于等温微量热技术实时测定和比较原研(罗氏芬)与仿制(MY)头孢曲松钠体外抑菌效果的快速检测方法。方法以金黄色葡萄球菌为测试菌株,利用微量热法,比较原研和仿制头孢曲松钠对金黄色葡萄球菌生长代谢的影响。以表达功率-时间曲线(热谱曲线)的特征参数:生长速率常数k、最大热功率Pm、热谱图出现主峰时间tm和传代时间tG为指标,量化评估原研和仿制头孢曲松钠对金黄色葡萄球菌生长代谢的影响。为验证等温微量热法结论,进一步采用管碟法和高效液相色谱法(HPLC)分别检测原研和仿制头孢曲松钠的抑菌活性。结果热谱曲线的特征参数数据表明,原研头孢曲松钠与仿制头孢曲松钠均具有抑菌活性,但原研头孢曲松钠抑菌效果比仿制头孢曲松钠明显,这一结论与传统管碟法及HPLC法所得结论一致。然而,等温微量热法实验仅需24h,管碟法与HPLC法则需48h以上。结论等温微量热技术具有灵敏度高、精密度好的特点,可实时检测和比较不同抗生素体外抑菌活性,在快速评价抗生素效价领域具备较好的应用前景。

Objective The purpose of this study was to establish a rapid,accurate,and more sensitive method to compare the anti-bacterial activity of the original(Rocephin®)and the generic ceftriaxone sodium.Methods The growth condition of Staphylococcus aureus under drugs was quantitatively evaluated by isothermal microcalorimetry with four characteristic parameters of the thermal power-time curves,including the growth constant(k),maximum thermal power(Pm),time to peak(tm),and generation time(tG).Furthermore,the cylinder-plate assay and the HPLC method were utilized to compare and confirm the inhibitory effect of the generic ceftriaxone sodium and that of the original.Results This work showed that the anti-bacterial activity of the original ceftriaxone sodium was stronger than that of the generic product based on isothermal microcalorimetry method.Additionally,results originated from isothermal microcalorimetry were verified by the cylinder-plate assay and the HPLC method.However,the isothermal microcalorimetry cost less than 24 hours,and the cylinder-plate assay and the HPLC method required more than 48 hours.Conclusion Isothermal microcalorimetry,which was sensitive,accurate,and useful technology,can be used as a promising method to compare the anti-bacterial activity of drugs.