Pharmaceutica Analytica Acta

Abstract

Multi-Dimensional Column Chromatographic Method with UV Detection, for the Determination of Propranolol at Therapeutic Levels in Human Plasma

Kamal A. al-Sagar and Malcolm R. Smyth

A simple and rapid HPLC assay method for the estimation of propranolol (InderalR) in human plasma was developed and validated. The method totally eliminates the extraction procedure; sample clean-up was achieved by on-line solid-phase extraction. The separation was achieved with μBondapack 10 μm C18 column (octadecylsilane, 30 cm×3.9 mm). The mobile phase consisted of a mixture of water, methanol, acetonitrile, acetic acid and triethylamine in the proportion of 160 ml: 80 ml: 70 ml: 2.5 ml: 125 μl, respectively. The pH was adjusted to 3.4 using 1 N NaOH before the addition of triethylamine. The mobile phase was filtered (0.2 μm filter) and degasified in a ultrasonic bath. The mobile phase flow rate was 0.5 ml/min. Detection was by UV detector at 291 nm and the retention time (RT) observed at around 8 minutes. The recovery of the drug from plasma was assessed by comparing the peak height of the extracted plasma samples with the peak height of authentic (un-extracted) standards which were directly injected (i.e. without column switching) into the analytical column at these concentration levels. The recovery values showed differences lower than 4.0% between the added amount and the founded amount, and were independent of the concentration. The response was linear over a range of 20-100 ng/ml with a limit of detection of 1 ng/ml and limit of quantification at 8 ng/ml plasma. This limit of quantification is adequate for clinical analysis and pharmacotherapeutic studies and comparable to those values obtained by other workers. The same method was used for the bioavailability study of propranolol formulation in healthy, human and male volunteers.