Determination of firocoxib in equine plasma using high performance liquid chromatography.

This research article discusses the development and validation of a new method for determining the presence of firocoxib, a nonsteroidal anti-inflammatory drug, in equine plasma using high performance liquid chromatography.

Objective of the Research

The primary goal of this research was to devise and validate a new analytical process for determining the presence and amount of firocoxib in equine plasma. Firocoxib is an NSAID commonly used in veterinary medicine for pain and inflammation management in horses and dogs, particularly in cases of osteoarthritis.

Methodology

• The team adopted a liquid extraction process. Ethyl acetate and hexane in a ratio of 40:60 were used for this purpose. Post extraction, samples were separated via an isocratic reversed-phase High Performance Liquid Chromatography (HPLC) approach.
• The chromatographic separation was performed on a Sunfire C(18) column, a versatile and commonly used column in HPLC due to its ability to withstand a wide range of pH values.
• To further quantify the amount of firocoxib, ultraviolet (UV) detection was performed at 290 nm.
• The mobile phase utilized during the method was a mixture of water, containing 0.025% trifluoroacetic acid, and acetonitrile, a powerful polar aprotic solvent that promotes separation of compounds.
• The flow rate was set at 1.1 ml/min during the experiment.

Results of the Research

• The method produced a linear response across the concentration range of 5-1500 ng/ml, with the lower limit of quantification set at 5 ng/ml.
• The variability in the results was found to be less than 7%, both within the same assay (intra-assay variability) and between different assays (inter-assay variability).
• The average recovery rate was estimated to be 98%, indicating high efficiency of the method.

Implications and Applications

• Based on the successful results of the research, the developed method proves to be suitable for analyzing clinical samples in pharmacokinetic studies. It provides a reliable method for assessing the amount of medication being absorbed into the horse’s body, how it is being distributed and how quickly it is being eliminated.
• This method is also advantageous as it can be used for samples of small volumes, thereby reducing the amount of plasma required for the analysis.