Determination of codeine in human plasma by reverse-phase high-performance liquid chromatography

Area of Science:

• Analytical Chemistry
• Pharmacokinetics
• Clinical Toxicology

Background:

• Accurate quantification of codeine in biological matrices is essential for therapeutic drug monitoring and pharmacokinetic studies.
• Existing methods may lack the sensitivity, specificity, or speed required for routine clinical analysis.

Purpose of the Study:

• To develop and validate a sensitive, precise, and specific high-performance liquid chromatographic (HPLC) method for codeine determination in human plasma.
• To establish a rapid analytical technique suitable for analyzing plasma codeine levels after therapeutic administration.

Main Methods:

• High-performance liquid chromatography (HPLC) with UV detection.
• Sample preparation involving C18 extraction column purification and addition of an internal standard.
• Separation on a reverse-phase C18 column with a slightly alkaline mobile phase.

Main Results:

• The developed HPLC method offers high specificity, precision, and sensitivity.
• The analysis time per run is 3.5 minutes.
• The limit of detection is approximately 3 µg/L, with an absolute recovery of 98.4% ± 6.7% in the 10-300 µg/L range.
• Linear calibration curves were observed within the tested concentration range.

Conclusions:

• The described HPLC method is suitable for accurate and efficient determination of codeine in human plasma.
• This validated method can be applied to assess plasma codeine concentrations in patients receiving therapeutic doses.
• The method's speed and sensitivity make it valuable for clinical and research applications in pharmacokinetics and toxicology.