Chromatographic conditions for analysis of sotalol HCl

The HPLC system consisted of a Hewlett Packard 1100 series (Agilent Technologies, Wilmington, DE, US) equipped with a quaternary pump, online degasser, column heater, autosampler and UV/Vis detector. Data collection and analysis were performed using ChemStation (Agilent Technologies). Separation was achieved on a Waters XBridge C18 3.5μm, 4.6×150 mm column protected using a XBridge C18 3.5 μm, 4.6×20mm security guard cartridge (Waters, Milford, MA, US). The elution was isocratic at 1.0 mL/min with a mobile phase of acetonatrile-0.5mM octanesulfonic acid (25:75, v/v, pH adjusted to 3.2). The column temperature was maintained at 30°C in a column oven, and auto-sampler was maintained at 20°C. The injection volume was 10 μL and detection was by UV at 235 nm. A calibration curve from 1–100 μg/mL was used to calculate the concentration of drug.