A dry-reagent strip for quantifying carbamazepine evaluated.

Area of Science:

• Clinical Chemistry
• Analytical Chemistry
• Biochemistry

Background:

• Carbamazepine is a crucial antiepileptic drug requiring therapeutic drug monitoring.
• Existing methods for carbamazepine quantification can be time-consuming or require specialized equipment.
• The apoenzyme reactivation immunoassay system (ARIS) offers a principle for developing rapid immunoassays.

Purpose of the Study:

• To evaluate a novel colorimetric homogeneous immunoassay for carbamazepine detection.
• To assess the assay's performance characteristics, including precision, accuracy, and interference.
• To determine the suitability of the assay for clinical use, particularly in time-sensitive situations.

Main Methods:

• Development of a dry-reagent strip immunoassay for carbamazepine.
• Utilizing the apoenzyme reactivation immunoassay system (ARIS) principle.
• Testing with the Ames Seralyzer reflectance photometer for quantitative analysis.

Main Results:

• The assay demonstrated excellent precision with within-run CVs ≤ 3.0% and between-run CVs ≤ 4.1%.
• High analytical recovery (99.9%) and strong correlation with fluorescence polarization immunoassay (r=0.995) and liquid chromatography (r=0.990) were observed.
• Minimal interference was noted from common biological substances, although high lipid and hemoglobin levels caused slight positive interference. Carbamazepine-10,11-epoxide showed cross-reactivity only at high concentrations (≥ 5 mg/L).

Conclusions:

• The new colorimetric homogeneous immunoassay for carbamazepine is accurate, precise, and reliable.
• The assay is rapid (80 seconds) and convenient, making it highly suitable for clinical settings requiring prompt results.
• The test's stability (calibration valid for ≥ 3 weeks) and ability to measure free carbamazepine further enhance its clinical utility.