Rapid and Reproducible RP-HPLC Method for Stability and Assay Determination of Enmetazobactam

Abstract

Abstract

Introduction:
Enmetazobactam is a next-generation diazabicyclooctane (DBO) β-lactamase inhibitor that lacks a β-lactam ring yet effectively restores the antibacterial activity of β-lactam antibiotics, particularly cefepime, against extended-spectrum β-lactamase (ESBL)–producing Gram-negative bacteria. Given its increasing clinical relevance, the availability of a validated analytical method is crucial for quality control, formulation development, and stability evaluation.

Materials and Methods:

A rapid and reliable reverse-phase high-performance liquid chromatographic (RP-HPLC) method was established and validated following ICH Q2 (R1) guidelines for the quantitative estimation of Enmetazobactam in bulk drug and pharmaceutical formulations. Chromatographic separation was achieved on a C18 column (150 × 4.6 mm, 5 µm) using a phosphate buffer–methanol mobile phase at a flow rate of 1.0 mL/min. Detection was performed using UV absorbance at 210 nm, yielding a retention time of approximately 6.5 minutes.

Results:
The method demonstrated excellent linearity over the concentration range of 70–130% of the target assay level, with a correlation coefficient exceeding 0.999. Precision and accuracy studies showed %RSD values below 2% and recovery results within 98–102%, confirming the reliability of the method. Forced degradation studies under acidic, alkaline, oxidative, photolytic, and thermal conditions established the specificity of the method, with clear separation of degradation products and no interference from formulation excipients. Analytical solutions remained stable for up to 15 hours when stored at 10°C, and system suitability parameters were within acceptable limits.

Conclusion:
The validated RP-HPLC method is simple, accurate, precise, and stability-indicating, making it suitable for routine quality control and stability testing of Enmetazobactam in bulk and dosage forms.