Model 1200 hplc uv

Solubility was measured separately at pH 7.4 by using an HPLC-UV method. Test compounds were initially dissolved in DMSO at 10 mg/mL. Ten microliters of this stock solution were spiked into either pH 7.4 phosphate buffer (1.0 mL) with the final DMSO concentration being 1%. The mixture was stirred for 4 h at room temperature, and then concentrated at 10,000 rpm for 5 min. The saturated supernatants were transferred to other vials for analysis by HPLC-UV and detected at 254 nm. Each sample was performed in triplicate. For quantification, a model 1200 HPLC-UV (Agilent) system was used with an Agilent Eclipse XDB-C18 column (150 × 4.6 mm, 5 m) and gradient elution of methanol (MeOH) in water, starting with 60% of MeOH, which was linearly increased up to 80% over 10 min, then slowly increased up to 90% over 15 min. The flow rate was 1.0 mL/min, and injection volume was 15 µL. Aqueous concentration was determined by comparison of the peak area of the saturated solution with a standard curve plotted as peak area versus known concentrations, which were prepared by solutions of test compound in acetonitrile (ACN) at 50 µg/mL, 25 µg/mL, 12.5 µg/mL, 3.13 µg/mL, 0.78 µg/mL, and 0.20 µg/mL.

Solubility was measured separately at pH 7.4 and 2.0 by using an HPLC-UV method. Test compounds were initially dissolved in DMSO at a concentration of 10 mg/mL. Ten microliters of this stock solution was spiked into either pH 7.4 phosphate buffer (1.0 mL) or 0.01 M HCl (approximately pH 2.0, 1.0 mL) with the final DMSO concentration being 1%. The mixture was stirred for 4 h at room temperature and then concentrated at 10000 rpm for 5 min. The saturated supernatants were transferred to other vials for analysis by HPLC-UV and detected at 254 nm. Each sample was analyzed in triplicate. For quantification, a model 1200 HPLC-UV (Agilent) system was used with an Agilent Eclipse XDB-C18 column (150 mm × 4.6 mm, 5 µm) and gradient elution of methanol (MeOH) in water, starting with 60% MeOH, which was linearly increased to 80% over 10 min and then slowly increased to 90% over 15 min. The flow rate was 1.0 mL/min, and the injection volume was 15 µL. The aqueous concentration was determined by comparison of the peak area of the saturated solution with a standard curve plotted as peak area versus known concentrations, which were prepared by solutions of the test compound in acetonitrile (ACN) at 50, 25, 12.5, 3.13, 0.78, and 0.20 µg/mL.

Solubility was measured at pH 7.4 by using an HPLC−UV method. Test compounds were initially dissolved in DMSO at a concentration of 1.0 mg/mL. Ten microliters of this stock solution was added to phosphate buffer (1.0 mL, pH 7.4). The mixture was stirred for 4 h at rt and then centrifuged at 3000 rpm for 10 min. The saturated supernatants were transferred to other vials for analysis by HPLC−UV. Each sample was performed in triplicate. For quantification, a model 1200 HPLC−UV (Agilent) system was used with an Agilent Eclipse XDB-C18 column (150 mm × 4.6 mm, 5 μm), and elution was with 50%−80% ACN in water. The flow rate was 0.8 mL/min, and injection volume was 20 μL. Aqueous concentration was determined by comparison of the peak area of the saturated solution with a standard curve plotted peak area versus known concentrations, which were prepared by solutions of test compound in ACN at 50, 12.5, 3.13, 0.78, and 0.20 μg/mL.