Determination of Gestodene in Human Plasma by SLE-LC-MS/MS Using a Solid Core HPLC Column

Significance of the Topic

Monitoring gestodene levels in plasma is critical for pharmacokinetic studies, bioequivalence trials and quality control of oral contraceptives. A sensitive, rapid method ensures accurate dosing, safety assessment and supports high-throughput bioanalysis in clinical and industrial laboratories.

Study Objectives and Overview

This study aimed to develop and validate a straightforward solid-liquid extraction (SLE) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) for quantifying gestodene in human plasma. The approach leverages a solid-core C18 column and deuterated internal standard to achieve high sensitivity over 0.05–5 ng/mL.

Methodology and Instrumentation

• Sample Extraction: HyperSep SLE cartridges with diatomaceous earth; plasma pre-treated with formic acid; analytes eluted with methyl tert-butyl ether, dried and reconstituted in 80:20 methanol/water.
• Chromatography: Thermo Scientific Accucore C18 2.6 μm, 50×2.1 mm column; gradient from 5% to 95% methanol (0.1% formic acid) over 5 min; flow rate 0.4 mL/min; column at 40 °C.
• Mass Spectrometry: TSQ Vantage triple-quadrupole; heated electrospray positive ionization; SRM transitions m/z 311.2→109.1 (gestodene) and 317.2→114.1 (d6-IS); instrument parameters optimized for sensitivity.
• Data Processing: LCQuan software with ICIS integration algorithm.

Main Results and Discussion

The analyte eluted at ~2.84 min with sharp peak shape. Calibration was linear (r2 = 0.999) across 0.05–5 ng/mL. Accuracy deviations were within ±5%, and intra-day precision at mid-range gave CV < 2%. Blank plasma showed no interferences, confirming method specificity.

Benefits and Practical Applications

• Fast 5-minute run time facilitates high throughput.
• Minimal solvent usage and automation potential reduce cost and variability.
• Low LLOQ (0.05 ng/mL) meets regulatory bioanalytical requirements.

Future Trends and Opportunities

Advances may include multiplexing with other steroids, integration with high-resolution MS, further miniaturization and greener extraction solvents. Automation enhancements promise greater throughput and reduced manual handling.

Conclusion

The described SLE-LC-MS/MS method is robust, rapid and precise, making it well-suited for routine quantification of gestodene in clinical and pharmaceutical bioanalysis.

Reference

1. Junior EA, Duarte LF, Vanunci MLP, Teixeira ML. Bioequivalence of Two Oral Contraceptive Drugs Containing Ethinylestradiol and Gestodene in Healthy Female Volunteers. J Bioequiv Availab 2010;2:125-130.
2. FDA Guidance for Industry: Bioanalytical Method Validation. U.S. Food and Drug Administration, 2012.