The assay and resolution of the beta-blocker atenolol from its related impurities in a tablet pharmaceutical dosage form.
For the complete resolution and determination of the beta-blocker atenolol and its manufacturing impurities a high-performance liquid chromatographic method is developed using structured optimization techniques. The method utilizes a 300 x 3.9 mm i.d. stainless steel column packed with mu Bondapak C18 and a mobile phase containing methanol-25 mM potassium dihydrogen orthophosphate containing 0.06% (v/v) dibutylamine (20:80, v/v) (pH 3.0). The flow rate of 1.0 ml min-1 is used and a detection wavelength of 226 nm. The linearity and repeatability are good for the present compound over the range 1.5-510.0 micrograms ml-1 (r greater than 0.99 and RSD 0.27%, n = 10). Application of the method to 50 and 100 mg tablets gave recoveries of 99% (w/w) and reproducibilities of (RSD) 1.1 and 0.52%, respectively (n = 5). The manufacturing impurities are found to be greater than 0.5% (w/w) of the atenolol peak.