Stability-indicating HPLC-DAD method for the simultaneous determination of fluoroquinolone in combination with a non-steroidal anti-inflammatory drug in pharmaceutical formulation

We developed and validated a stability-indicating assay method for the simultaneous determination of enrofloxacin and piroxicam in combination and in the presence of degradation products. Reverse-phase high-performance liquid chromatography analyses were carried out on a Vertisep C18 column and acetonitrile-water (48:52 v/v, pH 3.0) mobile phase with a 1.00 mL min−1 flow rate. The efficient chromatographic separation of these drugs and their forced degradation products was achieved in less than 5min with a peak purity match factor higher than 950. The method used showed linearity in the concentration ranges of 0.25 to 16.0 µg mL−1 for enrofloxacin (r = 0.9997) and 0.125 to 8.0 µg mL−1 for piroxicam (r = 0.9999) as well as precision (relative standard deviation lower than 2%), accuracy (mean recovery 100 ± 2%), and robustness, according to ICH (International Conference on Harmonization) and AOAC (Association of Official Analytical Chemists) guidelines. This method can simultaneously determine the combination of these drugs in a veterinary formulation and separate the drug peaks from their forced degradation products. Additionally, its optimized chromatographic conditions can contribute to the quality control of this formulation in pharmaceutical manufacturing plants and minimize waste from the organic solvent.

本研究开发并验证了一种稳定性指示分析方法，可同时测定复方制剂中的恩诺沙星(enrofloxacin)与吡罗昔康(piroxicam)，且可在降解产物共存的条件下完成定量分析。该方法采用反相高效液相色谱法进行分析，色谱柱为Vertisep C18柱，流动相为乙腈-水(48:52，体积比，pH 3.0)，流速为1.00 mL·min⁻¹。该方法可在5分钟内实现上述两种药物与强制降解产物的高效色谱分离，峰纯度匹配因子高于950。依据人用药品注册技术要求国际协调会(ICH, International Conference on Harmonization)与官方分析化学家协会(AOAC, Association of Official Analytical Chemists)的指导原则，该方法在恩诺沙星浓度范围0.25~16.0 μg·mL⁻¹（相关系数r=0.9997）、吡罗昔康浓度范围0.125~8.0 μg·mL⁻¹（相关系数r=0.9999）内均呈现良好线性关系；同时具备优异的精密度（相对标准偏差小于2%）、准确度（平均回收率为100%±2%）与耐用性。本方法可同时测定兽用复方制剂中的两种药物组分，并可将药物色谱峰与强制降解产物有效分离。此外，该方法优化后的色谱条件可助力制药生产企业对该制剂开展质量控制，并减少有机溶剂产生的废弃物。