CHEMOMETRIC EVALUATION OF DARIFENACIN HYDROBROMIDE USING A STABILITY-INDICATING REVERSED-PHASE LC METHOD

A set of chemometric tools including in silico simulation and design of experiments (DOE) was used to develop and validate an RP-LC/UV method for darifenacin hydrobromide. Retention factor (k′) from darifenacin and resolution (R) between darifenacin and degradation product were assessed by an exploratory study using organic modifier type, organic modifier content, mobile phase pH, flow rate, and column oven temperature as factors in a full factorial 25 design. The significant factors (organic modifier content, mobile phase pH, and column oven temperature) were selected and applied in a central composite design (CCD) with axial points positioned in α = 1.681. The optimum condition was obtained with Derringer's desirability. The validation was performed with a C8 (150 mm × 4.6 mm, 5 µm) column, wavelength 205 nm, 1.1 mL · min−1 flow rate, mobile phase with acetonitrile (MeCN) and orthophosphoric acid (OPA) 0.01% (v/v) pH 3.0 in a ratio 28:72 and column maintained at room temperature (25 ± 1°C). Forced decom...