Prazosin determination by high-pressure liquid chromatography using fluorescence detection.

Area of Science:

• Analytical Chemistry
• Pharmacology
• Clinical Chemistry

Background:

• Accurate quantification of prazosin is crucial for therapeutic drug monitoring.
• Existing analytical methods may lack sensitivity or require complex sample preparation.
• Prazosin stability in biological matrices is important for reliable analysis.

Purpose of the Study:

• To develop and validate a sensitive, reproducible HPLC method for prazosin analysis in whole blood and plasma.
• To establish a rapid sample preparation technique for routine clinical use.
• To assess the stability of prazosin under common storage conditions.

Main Methods:

• High-pressure liquid chromatography (HPLC) with fluorescence detection.
• Ion-pair chromatography using pentane sulfonic acid as the counter-ion.
• Validation of sensitivity, reproducibility, and accuracy in whole blood and plasma.
• Assessment of chromatographic separation in the presence of propranolol and quinidine.

Main Results:

• The method accurately quantifies prazosin as low as 0.2 ng/ml in whole blood and 0.5 ng/ml in plasma.
• High sensitivity and reproducibility were demonstrated with coefficients of variation of 5.6% and 5.4%, respectively.
• Chromatographic conditions were modified to ensure separation from propranolol and quinidine.
• Prazosin exhibited stability during short-term refrigeration and long-term freezing.

Conclusions:

• A validated, sensitive, and rapid HPLC method for prazosin analysis in biological samples is presented.
• The method is suitable for therapeutic drug monitoring and pharmacokinetic studies.
• Prazosin is stable in whole blood and plasma under specified storage conditions.