# A Cost-Effective Liquid Chromatography Method with Ultraviolet Detection for Identity Screening and Assay of Injectable Antibiotics

## TL;DR

This study developed a cost-effective liquid chromatography method to test the quality of injectable antibiotics in resource-limited settings.

## Contribution

A validated LC-UV method for identity screening and quantification of 13 injectable antibiotics in pharmaceutical formulations.

## Key findings

- The method achieved high linearity with R2 values greater than 0.999 for all antibiotics.
- Precision was excellent, with relative standard deviation values below 1%.
- All tested samples from Ethiopia met USP content specifications and contained the correct active pharmaceutical ingredient.

## Abstract

The presence of substandard and falsified (SF) medicines poses a significant challenge in resource-limited countries. Low-quality antibiotics are commonly reported in low-income countries. The present study aimed to develop and validate a liquid chromatography method with ultraviolet detection (LC-UV) for the identity screening and assay of 13 different injectable antibiotics, i.e., cefepime, amoxicillin, cefazolin, ampicillin, chloramphenicol, ceftazidime, ceftriaxone, cefotaxime, vancomycin, flucloxacillin, cloxacillin, benzylpenicillin, and meropenem in pharmaceutical formulations. Separation was performed using an XBridge C18 column and gradient elution. Mixtures of acetonitrile and 20 mM phosphate buffer (pH 8.0) were used as the mobile phases. The screening method was validated in terms of specificity and robustness, while linearity, precision, accuracy, and sensitivity were checked for the quantification method. The determination coefficients (R2) following linear regression were all greater than 0.999. The method showed good precision, with relative standard deviation values below 1%. The percentage recovery values were close to 100%. The method was applied to analyze 17 injectable antibiotics collected from the Ethiopian market. All commercial samples analyzed contained the correct API and met USP content specifications.