Determination of beta-blocker drugs in pharmaceutical preparations by non-suppressed ion chromatography

Sensitive spectrophotometric determination of atenolol in pharmaceutical formulations using bromate-bromide mixture as an eco-friendly brominating agent

Three simple and sensitive spectrophotometric methods are proposed for the determination of atenolol (ATN) in bulk drug and tablets. The methods are based on the bromination of ATN by the bromine generated in situ by the action of the acid on the bromate-bromide mixture followed by the determination of unreacted bromine by reacting with a fixed amount of either meta-cresol purple (MCP) and measuring the absorbance at 540 nm (method A) and 445 nm (method B) or erioglaucine (EGC) and measuring the absorbance at 630 nm (method C). Beer's law is valid within the concentration ranges of 1.0-20.0, 2.0-40.0 and 1.0-8.0 μg/mL for method A, method B and method C, respectively. The calculated molar absorptivities were found to be 1.20×10(4), 4.51×10(3) and 3.46 × 10(4)  L/mol · cm for method A, method B and method C, respectively. Sandell's sensitivity values, correlation coefficients, limits of detection and quantification are also reported. Recovery results were statistically compared with those of a reference method by applying Student's t- and F-test. The novelty of the present study is the measurement of two different colors using MCP, that is, red-pink color of MCP in acid medium at 540 nm and yellowish-orange color of brominated MCP at 445 nm.

Determination of metoprolol tartrate in tablets and human urine using flow-injection chemiluminescence method

In this paper, a simple, rapid and sensitive flow-injection chemiluminescence method has been developed for the determination of metoprolol tartrate, which acts as a kind of sensitizer in the chemiluminescence emission from the redox of SO(3)(2-) with Ce(IV) in acidic medium. Under the optimized conditions, the proposed method allows the measurement of metoprolol tartrate over the range of 1.5 x 10(-8) to 7.3 x 10(-6)mol/L with a detection limit of 4.7 x 10(-9)mol/L (3sigma), and the relative standard deviation for 7.3 x 10(-7)mol/L metoprolol tartrate (n=11) is 2.20%. The utility of this method was demonstrated by determining metoprolol tartrate in tablets and human urine sample.