Improved high-performance liquid chromatographic method for analysis of cyclosporin A using an automated sample...

Area of Science:

• Clinical Chemistry
• Pharmacology
• Analytical Chemistry

Background:

• Transplant patients require precise monitoring of cyclosporin A levels due to its narrow therapeutic range.
• Existing methods may lack the stability, accuracy, or reproducibility needed for routine therapeutic drug monitoring.

Purpose of the Study:

• To develop and validate a stable, accurate, and reproducible high-performance liquid chromatographic (HPLC) method for cyclosporin A analysis in whole blood.
• To establish a reliable assay for routine monitoring of cyclosporin A in transplant recipients.

Main Methods:

• Development of an HPLC method utilizing the Varian Advanced Automated Sample Processor.
• Analysis of cyclosporin A and internal standard recovery from 200 microliters of whole blood.
• Validation of assay linearity, detection limit, and coefficient of variation.

Main Results:

• Achieved 81% absolute recovery for cyclosporin A and internal standard.
• Established a detection limit of 12.5 ng/ml and perfect linearity (r² = 1.0) over the 0-1000 ng/ml range.
• Demonstrated high precision with a coefficient of variation of 1.87% at 250 ng/ml and a cycle time of 10.2 min per sample.

Conclusions:

• The developed HPLC method is stable, accurate, and reproducible for cyclosporin A quantification in whole blood.
• The assay's efficiency allows for high-throughput analysis, processing up to eighty samples per day with results within 16 hours.
• This method provides a reliable tool for therapeutic drug monitoring of cyclosporin A in transplant patients.