HPLC on Chiralcel OJ-R for enantiomer separation and analysis of ketoprofen, from horse plasma, as the 9-aminophenanthrene derivative.

The research article presents a study on the separation and analysis of the enantiomers of ketoprofen, a non-steroidal anti-inflammatory drug used in horses, from horse plasma using a specific high-performance liquid chromatography technique. The results reveal significant bio-inversion of one isomer to another in horses, as well as notable inter-animal variation.

Methodology

• The researchers employed a chiral stationary phase known as cellulose tris(4-methylbenzoate) or Chiralcel OJ-R to study the enantioselective chiral inversion of ketoprofen administered to horses.
• The mobile phase utilized was a mixture of acetonitrile, 0.02 M perchlorate buffer with a pH of 2.0, and methanol in the volumetric ratio of 60:15:25.
• Prior to chromatography, ketoprofen was derivatized with 9-aminophenanthrene under acidic conditions. This was done following solid-phase (C18) extraction and liquid-liquid extraction in order to effectively remove any endogenous materials from the plasma.
• The researchers used the 9-aminophenanthrene derivative of S-ibuprofen as an internal standard.

Results

• The enantiomers of ketoprofen were successfully separated to the baseline with an Rs value of 6.44 and an alpha value of 1.76 within a short analysis time.
• The results revealed that there was significant bio-inversion of R-ketoprofen to the S isomer in horses.
• However, there were significant differences noted in the pharmacokinetic parameters across the sample population, indicating a high degree of inter-animal variation.

Conclusions

• The findings of this study can enhance understanding of how ketoprofen, a common non-steroidal anti-inflammatory drug used in equines, behaves differently in different animals.
• This research underlines the need for personalized dosing strategies in veterinary medicine, particularly when it comes to non-steroidal anti-inflammatory drugs.
• Furthermore, these results might lead to the development of more effective and safer pain management therapies for horses in the future.