HPLC method development for testosterone propionate and cipionate in oil-based injectables

Two isocratic liquid chromatographic methods for the determination of testosterone propionate (TP) and cipionate (TC) in oil-based injectables using methyltestosterone and bolasterone as internal standards, respectively, have been developed and validated. Mobile phases 57% water:acetonitrile 43% (v:v) and 54% water:acetonitrile 46% (v:v) were used for TP and TC, respectively. For both methods, a bonded-silica Luna CN (250 mm × 4.6 mm i.d., 5 μm) (25 °C) column, a flow-rate 1 ml min−1 and UV absorbance detection at 245 nm were used and two separations up to base line were achieved. Prior to HPLC analysis, sample preparation was required, including extraction of TP and TC from oil-based injectables using the surfactant sodium dodecyl sulphate.