Plasma pentobarbitone levels. Estimation by gas-liquid chromatography after clinical doses

Area of Science:

• Pharmacology
• Analytical Chemistry
• Clinical Diagnostics

Background:

• Accurate quantification of pentobarbitone in plasma is crucial for therapeutic drug monitoring and pharmacokinetic studies.
• Existing methods for pentobarbitone estimation may be time-consuming or require specialized equipment.

Purpose of the Study:

• To develop and validate a simple, rapid, and reliable method for estimating pentobarbitone concentrations in human plasma.
• To assess the utility of glutethimide as an internal standard for this assay.

Main Methods:

• Plasma samples were subjected to ether extraction to isolate pentobarbitone.
• Gas-liquid chromatography (GLC) was employed for the quantitative analysis of pentobarbitone.
• Glutethimide was utilized as the internal standard to ensure assay accuracy and precision.

Main Results:

• The developed method demonstrated reproducibility for plasma samples obtained after oral or intramuscular administration of 100 mg pentobarbitone.
• Glutethimide proved to be a reliable internal standard, contributing to the robustness of the assay.
• Recommended sample preparation involves evaporation at 37°C and storage at -20°C prior to analysis.

Conclusions:

• A simple and efficient ether extraction and GLC method for pentobarbitone plasma estimation has been established.
• This method provides reproducible results, making it suitable for routine clinical and research applications.
• The use of glutethimide as an internal standard enhances the reliability of pentobarbitone quantification in plasma.