A validated capillary electrophoretic method for the determination of indacaterol and its application to a...

Indacaterol is a new inhaled ultra-long acting β₂-agonist. It has been recently approved in the European Union for the treatment of chronic obstructive pulmonary disease. This paper reports, for the first time, a method for the determination and validation of Indacaterol (IND) using an internal standard in capsules. Capillary electrophoretic separation was performed on an uncoated fused-silica capillary (50 cm effective length, 75 μm i.d.) and background electrolyte composed of 20 mmol L^-1 of sodium tetraborate buffer, 15% (v/v) methanol (pH = 10.0) with the application of 20 kV of potential; 10 s at 5 × 10³ N m^-2 (50 mbar) of injection time; and wavelength of 200 nm and 25 °C of temperature. The linearity was evaluated in the range of 4.90 × 10^-6 mol L^-1 (2.50 μg mL^-1) and 3.94 × 10^-5 mol L^-1 (20.00 μg mL^-1), with R = 0.9993 for inter-day. LOD and LOQ values were 2.18 × 10^-8 mol L^-1 (0.011 μg mL^-1) and 7.25 × 10^-8 mol L^-1 (0.037 μg mL^-1) for inter-day, respectively. The precision values were 0.50-1.06% for intra-day and 2.12% for inter-day as RSD%. The accuracy was tested by the standard addition method with the recovery values being between 98.79 and 99.09 as percentages with RSD% interval of 0.01-0.80. The developed method was validated according to ICH guidelines. Indacaterol was successfully determined in Arcapta^® capsule dosage form by the validated CE method with a relative error of 0.28%. The result was within the requirements of the USP 34-NF29. Therefore, the validated method may be used for the determination of Indacaterol in its capsules in quality control laboratories.