Rapid and sensitive method for quantification of gestodene in human plasma as the oxime derivative by liquid chromatography–tandem mass spectrometry (LC–MS/MS) and its application to bioequivalence study

• Novel method for the estimation of gestodene in human plasma as oxime derivative.
• Derivatization technique applied for quantitation of gestodene in human plasma.
• Sensitive method for gestodene with limit of quantification 50 pg/ml.
• Better cleanup using solid phase extraction method.

A rapid and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) method has been developed and validated for the estimation of gestodene in human plasma. Gestodene was extracted from human plasma by using solid-phase extraction technique. Gestodene D6 was used as the internal standard. An Acquity HSS-T3 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The mass transition ion-pair was followed as m/z 326.2 → 124.1 for gestodene and m/z 332.3 → 129.1 for gestodene D6. The method involves a solid phase extraction from plasma, rapid derivatization with hydroxylamine to form oxime, simple gradient chromatographic conditions and mass spectrometric detection that enables detection at sub-picogram levels. The proposed method has been validated for a linear range of 50–11957 pg/ml with a correlation coefficient ≥ 0.9994. The intra-run and inter-run precision and accuracy were within 10%. The overall recoveries for gestodene and gestodene D6 were 62.02% and 67.57% respectively. The total run time was 4.0 min. The developed method was applied for the determination of the pharmacokinetic parameters of gestodene following a single oral administration of a 2 × 0.06 mg gestodene tablets in 10 healthy female volunteers.