Determination of 2′,3′-dideoxycytidine in maternal plasma, amniotic fluid, placental and fetal tissues by high-performance liquid chromatography

2′,3′-Dideoxycytidine (DDC) is a nucleoside reverse transcriptase inhibitor that has been shown to inhibit the human immunodeficiency virus (HIV). DDC is a candidate for treatment of pregnant women to prevent prenatal transmission of HIV/AIDS to their unborn children. A quick and simple high-performance liquid chromatography (HPLC) method has been developed and validated for the determination of DDC concentrations in samples collected from a pregnant rat model (maternal plasma, amniotic fluid, placental and fetal tissues). Extraction of DDC and its internal standard 2′,3′-dideoxy-3′-thiacytidine (3TC) in plasma and amniotic fluid was carried out by protein precipitation. Extraction from placental and fetal homogenates was achieved by solid phase extraction using Waters Oasis HLB solid phase extraction cartridges. Chromatographic separation was achieved on a Waters Spherisorb S3W silica column (4.6 mm × 100 mm) equipped with a Phenomenex guard column. The mobile phase used was 10% methanol in water with 22 mM formic acid. The flow rate was 0.5 ml/min, and the detection wavelength was optimized at 275 nm. Under these chromatographic conditions, DDC eluted around 12 min, and 3TC eluted around 10 min. The calibration curves for each day of validation and analysis showed good linear response through the range of 0.15–75.0 μg/ml in each of the four matrices. The relative recovery for DDC in each of the matrices ranged from 87.8% to 103.0%. Acceptable intra- and inter-day assay precision (<15% R.S.D.) and accuracy (<15% error) were observed over 0.15–75.0 μg/ml for all four matrices.