Simultaneous determination of amoxicillin and chloramphenicol and their drug interaction study by the validated UPLC method

A new UPLC method was developed for the simultaneous estimation of amoxicillin and chloramphenicol in pharmaceutical formulations. Drugs were resolved on Shim-Pack XR-ODS (2 mm i.d. × 50 mm, particle size 2.2 μm) reverse-phase column, utilizing a mobile phase of methanol:0.0025 M ammonium acetate in the initial ratio 40:60 (v/v) at a gradient program. The mobile phase was pumped at a flow rate of 0.25 mL/min with detection at 220 nm. 10 μL volume of sample was injected by the auto sampler. Separation was completed within 2.72 ± 0.03 min. Calibration curves were linear with correlation coefficient 0.999 over a studied concentration range of 10 μg mL−1 for both drugs. Method was found to be reproducible with relative standard deviation (RSD) for intra- and interday precision to be <1.5% over the said concentration range. The mean recovery of the drug from the standard solution was 99.39%. LOD was found to be 0.03 and 0.025 μg mL−1 for amoxicillin and chloramphenicol, respectively. The proposed method is simple, fast, accurate, precise and reproducible hence, it can be applied for routine quality control analysis of amoxicillin and chloramphenicol in bulk and pharmaceutical formulations. Furthermore, study revealed that adverse drug interaction due to their concomitant use is not from pharmaceutical interaction.