Quantitative high-performance liquid-chromatographic method for determining disopyramide (Norpace) in serum

Area of Science:

• Analytical Chemistry
• Clinical Chemistry
• Pharmacokinetics

Background:

• Disopyramide is an antiarrhythmic drug requiring therapeutic drug monitoring.
• Accurate quantification of disopyramide in biological matrices is crucial for patient management.

Purpose of the Study:

• To develop and validate a sensitive and specific high-performance liquid-chromatographic (HPLC) method for disopyramide serum measurement.

Main Methods:

• Serum samples (0.5 ml) were extracted with chloroform containing p-chlorodisopyramide as an internal standard.
• Separation was performed on a reversed-phase octadecylsilyl column at room temperature.
• Detection was achieved at 254 nm.

Main Results:

• The method demonstrated sensitivity down to 0.2 mg/L with linearity up to 10 mg/L.
• Within-day and day-to-day precision (CV) were below 10% at various concentrations.
• Average recovery was 98%, with minimal interference from over 85 other drugs.

Conclusions:

• This HPLC method provides a reliable, sensitive, and specific means for quantifying disopyramide in serum.
• The assay is suitable for routine clinical laboratory use and pharmacokinetic studies.