A Simple and Reliable RPLC Method for Simultaneous Determination of Five β-Blocker Drugs in Pharmaceuticals and Human Plasma

A simple and reliable simultaneous determination of β-blocker drugs (acebutolol, pindolol, atenolol,nadolol and oxprenolol) was accomplished by reversed phase liquid chromatography-ultravioletdetection (RPLC/UV). The chromatographic separation was achieved on a SB-C18 ZORBAX® column(250 mm × 4.6 mm i.d., 5 micron), using a mobile phase consisted of 0.02 mol L-1 phosphate buffer(pH = 3.5)-acetonitrile (70:30, v/v). Isocratic elution was used at a flow rate of 1.0 mL min-1. The UVdetector was operated at 230 nm and the column temperature was maintained at 30 °C. Under optimalconditions, a good linearity in the range of 10-500 μg L–1 for five β-blocker drugs with the correlationof determinations (R2) higher than 0.9971 was achieved. The proposed method was successfully appliedto routine analysis of several β-blockers in pharmaceutical tablets. Moreover, the results obtained fromthis study demonstrated that the validated method can be successfully used to routine analyze thetherapeutic concentrations of several β-blockers in human plasma. The LOD and LOQ for selectedβ-blockers were ranged within 0.050-0.538 and 0.152-1.794 μg L-1 & 0.192-0.845 and 0.641-2.562μg L-1, respectively, for pharmaceutical and plasma samples. Results of intra-day and inter-day precisionexpressed in terms of %RSD were found to be less than 2.0. Accuracy of the RPLC method wasassessed by performing replicate analyses of selected β-blockers in samples against a calibrationcurve indicating high recoveries within 96.7-110.5%. This new method could be used for analysis oflarge sample series of five β-blockers in routine laboratory work.