Stability indicating RP-HPLC method for simultaneous determination of gatifloxacin and dexamethasone in binary combination

Syed Naeem Razzaq,Islam Ullah Khan,Ghulam Mustafa,Syed Saleem Razzaq,Muhammad Ashfaq,Irfana Mariam,Muhammad Zubair

doi:10.1590/s2175-97902017000115177

Abstract

In this study, conditions were optimized for development of a simple RP-HPLC method for simultaneous analysis of gatifloxacin and dexamethasone in different matrices like pharmaceuticals, human serum and urine. Good separation of gatifloxacin and dexamethasone from the induced degradation products was accomplished using C8 as stationary phase; 0.02 M phosphate buffer (pH 3.0) and methanol (42:58 v/v) as mobile phase. The concentration was measured with DAD at 270 nm. Linearity was observed in the range of 0.000040-0.000280 mol/L for gatifloxacin (r2≥0.999) and 0.000013-0.000091 mol/L for dexamethasone (r2≥0.999). Both the analyte peaks were completely separated from the peaks of induced degradation products as indicated by the peak purity index (≥0.9999 for both analytes). The optimized method is recommended to be used for concurrent analysis of gatifloxacin and dexamethasone in different matrices.

Highlights

Gatifloxacin (Figure 1A), a broad spectrum antibiotic is primarily used to treat bacterial infections like conjunctivitis, keratitis, pre and post-operative (Martindale, 2009)
Reverse phase (RP) chromatography has been used widely in the last two decades for the separation of many organic molecules pharmaceuticals because of containing major non-polar groups as well as containing unsaturated π electrons. As both the investigating pharmaceuticals have this common feature in their structure, so in this study, an RP-HPLC was developed for simultaneous analysis of gatifloxacin and dexamethasone in different matrices like pharmaceuticals, human serum and urine
In order to develop a method that can quantify both of these simultaneously, we took advantage of the problems faced during the previous studies, where dexamethasone peak showed high tailing on C18, Phenyl-2, and Cyano columns but symmetrical/good peak on C8 (Razzaq et al, 2013; 2014; Khan et al, 2014)

Summary

Introduction

Gatifloxacin (Figure 1A), a broad spectrum antibiotic is primarily used to treat bacterial infections like conjunctivitis, keratitis, pre and post-operative (Martindale, 2009). Dexamethasone (Figure 1B), a corticosteroid, used primarily for ocular inflammation conditions and where the risk of bacterial ocular infection or its risk is found (Martindale, 2009). The estimation of dexamethasone has been reported widely by HPLC (Iqbal et al, 2006; Huetos et al, 1999; Mallinson et al, 1995; Chen et al, 2008; Lemus Gallego, Pérez Arroyo, 2002; Cocenza, Mainardes, Gremião, 2009; Kwak, D’Amico, 1995), GC-MS (Mallinson et al, 1995) and TLC (Huetos et al, 1999).

Methods

Results

Conclusion