Validation of Two High-Performance Liquid Chromatographic Methods for the Analysis of Nadolol and Propranolol Hydrochloride Following In Vitro Transdermal Diffusion Studies

Nadolol and propranolol are beta-blockers used to prevent the onset of migraines. Two simple and rapid High Performance Liquid Chromatographic (HPLC) methods with ultraviolet detection were evaluated in order to establish their efficacy for detecting nadolol and propranolol hydrochloride in samples obtained from in vitro transdermal absorption studies. Both methods were validated for specificity, linearity, precision, accuracy, limit of detection, limit of quantification and robustness. Moreover, the stability of both drugs in a buffered solution was assessed. Separation was carried out on a 250 mm Kromasil® C18 column at room temperature. When nadolol was analysed, the detector response at 269 nm was found to be linear in a concentration range of 0.17 to 167 μM. In the case of propranolol hydrochloride, a fixed wavelength of 291 nm for quantification corresponded with calibration lines in the range of 0.11 to 113 μM. The limits of detection (LOD) and quantification (LOQ) were 0.058 and 0.038 μM and 0.171 and 0.115 μM for nadolol and propranolol hydrochloride, respectively. The maximum relative error and relative standard deviation detected were 5.19% and 6.08% respectively for nadolol and 3.57% and 6.44% respectively for propranolol hydrochloride. The results of robustness were highly satisfactory.