Quantitative analysis of Cefpodoxime Proxetil raw material and dry suspension using proton nuclear magnetic resonance

This study established a simple,rapid,and accurate nuclear magnetic resonance(NMR)quantitative method to determine the cefpodoxime proxetil content in raw materials and dry suspensions,and evaluated the uncertainty.The relative content of cefpodoxime proxetil iso-A and iso-B was also analyzed based on 1H NMR.In this study,an internal standard method was used,with DMSO-d6 as the solvent and maleic acid and 1,3,5-trimethylbenzene as internal standards,to calculate the concentration of the samples.Quantitative analysis was performed using both the traditional quantitative NMR(traditional qNMR)and the quantitative Global Spectral Deconvolution(qGSD)method.The linearity range,quantitation limit,precision,robustness,and accuracy of these quantitative analysis methods were validated.The results indicated that both internal standards and integration methods met the requirements of the“9101 Guidelines for Analytical Method Validation”in the 2020 edition of the Chinese Pharmacopoeia.Compared to the traditional qNMR,qGSD has unique advantages in accurate quantitative analysis in complex systems.By using the combined HPLC-SPE-NMR technique,cefpodoxime proxetil iso-A and iso-B were enriched and analyzed,and their NMR data were accurately assigned.The quantitative analysis results were in line with the requirements of the Chinese Pharmacopoeia.

Development of a new single dose extended release formulation of cefpodoxime proxetil

Objective:To develop floating microspheres of cefpodoxime proxetil(CP) in order to achieve an extended retention in the upper GIT for 12 hour.Methods:The microspheres were prepared by non aqueous solvent evaporation method using different ratios of cefpodoxime proxetil, hydroxyl propyl methyl cellulose(HPMC K4M ) and ethyl cellulose(1:1:1,1:1:2,1:1:3,1:1:4, 1:1:5 & 1:1:6),in the mixture of dichloromethane and ethanol at ratio of(l:l),with tween80 as the surfactant.Results:The floating microspheres was extended over 10-12 hours and were characterized by particle size analysis(75-600μm),buoyancy percentage(68.1%-85.4%), drug entrapment efficiency(67.5%-88.8%),%yield(50.50%-77.31%) and in vitro drug release was studied for 12 hours.Conclusions:The floating microspheres show better result and it may be use full for prolong the drug release in stomach and improve the bioavailability.

Characterization of impurities in cefpodoxime proxetil using LC–MS^(n)

Reversed-phase liquid chromatography coupled with electrospray ionization tandem mass spectrometry(ESI-MS/MS)was used to characterize impurities in cefpodoxime proxetil,an ester-modified prodrug.Based on the mechanisms by which cephalosporins are degraded,stress tests were designed and performed.The bulk material and capsule were eluted through a C18 column with formic acid–methanol–water as the mobile phase.In total,15 impurities were characterized in commercial samples,including 7 known impurities and 8 new impurities.The structures of these unknown compounds were deduced via comparison with the fragmentation patterns of cefpodoxime proxetil.Data from this systematic study will help improve the safety and quality of cefpodoxime proxetil.