Pharmacophore an International Research Journal
A simple, sensitive, accurate and stability-indicating economical densitometric method has been developed and validated for the quantitative determination of linagliptin in bulk and pharmaceutical dosage forms. Separation of the drug was carried out using ethyl acetate: IPA : Ammonia 7:3:0.4 (v/v/v) as mobile phase on precoated silica gel 60 F254 plates. The retention factor (Rf ) for linagliptin was 0.61 ± 0.05. The detection of band was carried out at 225 nm. The method is validated with respect to linearity, accuracy, precision, robustness and forced degradation studies, which further proves the stability-indicating supremacy of the method. During forced degradation studies, linagliptin is observed to be labile to acid, base hydrolysis and oxidative stress and stable in photolytic and thermal stress. The degradation products are well separated from the linagliptin peak, thus proving the stability-indicating superiority of the method. The calibration curve was linear in the concentration range 100 to 700 ng per band with correlation coefficient (r2 = 0.997) and is found to be sensitive for linagliptin, with a detection limit of 47 ng per band and a quantification limit of 142 ng per band. The proposed method is simple, rapid and economical when compared to liquid chromatographic method for the determination of linagliptin in bulk and pharmaceutical dosage form.
