Quantitative determination of crystal type Ⅰ in meropenem for injection by powder X-ray diffraction
Objective To quantitatively analyze and compare the crystal type Ⅰ in meropenem for injection from three companies by powder X-ray diffraction(PXRD).Methods Using fine scanning method,a calibration curve was established by correcting the characteristic peak intensity at 2θ=12.9° with the mass of mixed sample as the quantitative parameter.The content of crystal type Ⅰ was determined from three companies and compared with total content in HPLC method.Results When the content of meropenem crystal type Ⅰ was 5%~120%,the calibration curve was Y =553.8 X-105.9(r=0.998 4).The content of crystal type Ⅰ in the preparations from three companies was slightly lower than the total content of meropenem.Conclusion The method established in this paper is simple and fast,and can be used for the content analysis of meropenem crystal type Ⅰ without interference of excipients.It can provide a reference for the quality control and crystal type stability of meropenem for injection.