[Measuring linezolid in biological fluids using high-efficiency liquid chromatography].

Area of Science:

• Analytical Chemistry
• Pharmacology

Background:

• Accurate quantification of antibiotics in biological matrices is crucial for therapeutic drug monitoring and pharmacokinetic studies.
• Linezolid is an important antibiotic used to treat serious Gram-positive bacterial infections.

Purpose of the Study:

• To develop and validate a high-efficiency liquid chromatography (HELC) method for determining linezolid concentrations.
• To assess the method's applicability in various biological fluids such as plasma, vitreous humour, and cerebrospinal fluid.

Main Methods:

• Linezolid was extracted from biological samples using protein precipitation with perchloric acid.
• Chromatographic separation was achieved using a C18 stationary phase and a mobile phase of K2HPO4 buffer and acetonitrile.
• Ultraviolet detection at 254 nm was employed for quantification.

Main Results:

• The HELC method demonstrated excellent accuracy (94.4-106.1%) and precision (intra-day: 0.88-6%, inter-day: 3.7-5.6%).
• Recovery from plasma samples was high (93%), and the method proved linear across the studied concentration range.
• The assay is sensitive, fast, and cost-effective.

Conclusions:

• The validated HELC method is reliable for accurate linezolid quantification in diverse biological matrices.
• This method provides a robust foundation for future clinical pharmacokinetic investigations of linezolid.
• The assay's efficiency and cost-effectiveness make it suitable for routine clinical and research applications.