头孢吡肟/阿维巴坦M-H肉汤中浓度测定方法学建立及在体外动态PK/PD模型中的应用

Development and validation of a method for quantitation of cefepime/avibactam in M-H broth:application to antibacterial activity using in vitro PK/PD Model

目的:建立头孢吡肟和阿维巴坦在Mueller-Hinton(M-H)肉汤中浓度测定方法,并于头孢吡肟/阿维巴坦体外动态药代动力学/药效学(phar-macokinetic/pharmacodynamic,PK/PD)模型中进行初步应用。方法:采用高效液相色谱法(HPLC)对M-H肉汤中头孢吡肟进行测定;采用液质联用法(LC-MS/MS)对M-H肉汤中阿维巴坦进行测定。建立头孢吡肟/阿维巴坦2.5 g q8 h给药方案下体外动态PK/PD感染模型,进行头孢吡肟/阿维巴坦抗碳青霉烯类耐药肺炎克雷伯菌(carbapenem-re-sistant Klebsiella pneumoniae,CRKP)抗菌作用研究。结果:头孢吡肟和阿维巴坦在0.5~120μg/mL和0.1~25μg/mL线性关系良好(r=0.999),定量下限浓度为0.5、0.1μg/mL,肉汤培养基中头孢吡肟和阿维巴坦的的提取回收率分别为88.0%~101.7%和90.9%~95.2%。日内、日间RSD均小于5.2%。在体外PK/PD模型中,头孢吡肟和阿维巴坦具有良好的拟合度,实测浓度在理论浓度的±20%范围内。对于MIC=8μg/mL和MIC=16μg/mL的CRKP,头孢吡肟阿维巴坦2.5gq8h的给药方案在24 h时菌落分别下降2.783 Log10 CFU/mL、1.325Log10CFU/mL。结论:本研究建立的头孢吡肟及阿维巴坦在肉汤中浓度测定方法灵敏度高、稳定性好。体外动态PK/PD模型显示头孢吡肟阿维巴坦常规给药下对MIC≤8μg/mL的CRKP具有较好的抗菌活性。

AIM:To establish a method for quanti-tation of cefepime and avibactam in M-H broth,and applicated in the in vitro dynamic PK/PD mod-el.METHODS:The cefepime was also determined using the high-performance liquid chromatography method(HPLC),the avibactam was also determined using the liquid chromatography-mass spectrome-try(LC-MS/MS),an in vitro dynamic PK/PD model was established to study the PK/PD relationship of cefepime/avibactam against carbapenem resistant Klebsiella pneumoniae(CRKP).RESULTS:The linear ranges of cefepime and avibactam were good at(0.5-20)and(0.1-25)μg/mL(r=0.999),and the low-er limit concentrations were 0.5 and 0.1μg/mL.The extraction recoveries of cefepime and avibac-tam in M-H broth were 88.0%-101.7%and 90.9%-95.2%,the relative standard deviation of intra-day precision and inter-day precision were less than 5.2%.The concentration-time curves were well sim-ulated by the PK/PD model.All observed concentra-tions in each experiment were in the range of 20%of the targeted values.For the CRKP of MIC=8μg/mL and MIC=16μg/mL,the colony decreased to 2.783Log10 CFU/mL and 1.325Log10 CFU/mL at the cefepime/avibactam 2.5 g q8 h administration after 24 h.CONCLUSION:The determination method of cefepime and avibactam in broth established in this study has high sensitivity and good stability.For the CRKP with MIC≤8μg/mL,cefepime/avibactam showed that good anti-CRKP activity under routine administration in vitro dynamic PK/PD model.