Capillary GLC assay for carbinoxamine and hydrocodone in human serum using nitrogen-sensitive detection

Area of Science:

• Analytical Chemistry
• Pharmacology

Background:

• Accurate quantification of pharmaceuticals in biological matrices is crucial for therapeutic drug monitoring and pharmacokinetic studies.
• Simultaneous analysis of multiple drugs can improve efficiency and reduce costs in clinical laboratories.

Purpose of the Study:

• To develop and validate a capillary gas chromatography method for the simultaneous determination of carbinoxamine and hydrocodone in human serum.
• To assess the method's sensitivity, linearity, and precision for reliable quantification.

Main Methods:

• Capillary gas chromatography with NP-FID detection was employed.
• A multi-step liquid-liquid extraction procedure was used to isolate the drugs and internal standards from serum.
• Temperature programming of the fused silica column facilitated separation.

Main Results:

• The method demonstrated linear calibration curves up to 20 ng/ml for both carbinoxamine and hydrocodone.
• Coefficients of variation were low, averaging +/- 6.1% for carbinoxamine and +/- 5.0% for hydrocodone.
• The method achieved a sensitivity of approximately 0.2 ng/ml for a 2-ml serum sample.

Conclusions:

• The developed capillary gas chromatography method is suitable for the simultaneous analysis of carbinoxamine and hydrocodone in human serum.
• This method provides a sensitive, precise, and reliable tool for pharmacokinetic and clinical studies involving these drugs.