An improved micromethod for vancomycin determination by high-performance liquid chromatography

Area of Science:

• Analytical Chemistry
• Clinical Chemistry
• Pharmacokinetics

Background:

• Vancomycin is a critical antibiotic for treating serious Gram-positive bacterial infections.
• Accurate therapeutic drug monitoring of vancomycin is essential to optimize efficacy and minimize toxicity.
• Existing analytical methods may require larger sample volumes or longer analysis times.

Purpose of the Study:

• To develop and validate a sensitive, rapid, and precise micromethod for quantifying vancomycin in human serum or plasma.
• To establish a reliable analytical technique suitable for routine clinical laboratory use.
• To assess the method's accuracy, linearity, and interference from co-administered drugs.

Main Methods:

• Development of a reversed-phase high-performance liquid chromatography (RP-HPLC) micromethod.
• Utilized ristocetin as an internal standard.
• Employed an amino propyl column with a specific mobile phase (62% acetonitrile/38% sodium phosphate buffer, pH 7.0) and UV detection at 225 nm.
• Validated linearity over a range of 1.0–100 µg/mL.

Main Results:

• The developed micromethod demonstrated excellent linearity (correlation coefficient > 0.999) between 1.0 and 100 µg/mL.
• Achieved near-complete recovery of vancomycin from serum samples.
• No significant interference was observed from commonly prescribed medications.
• The assay requires a small sample volume (50 µL) and has a short run time (10 min).

Conclusions:

• The developed RP-HPLC micromethod is a simple, sensitive, rapid, precise, and selective assay for vancomycin analysis in human serum or plasma.
• This method is suitable for therapeutic drug monitoring, offering advantages in sample volume and speed.
• The assay's reliability and lack of interference support its clinical utility.