A Very Simple and
Sensitive Spectrofluorimetric Method Based on the Oxidation with Cerium (IV)
for the Determination of Four Different Drugs in Their Pharmaceutical
Background: Methyldopa is a catecholamine
widely used as an antihypertensive agent.
Pioglitazone is an oral
anti-hyperglycemic agent. It is used for the treatment of diabetes mellitus
type 2. A survey
of the literature reveals that only one spectrofluorimetric method has been
reported for the determination of pioglitazone in
pharmaceutical preparations. Atenolol and metoprolol are prescription drugs of
the β-blocker class with hypotensive action to treat angina, MI, alcohol
and arrhythmias. A survey of the literature reveals that several
spectrofluorimetric methods have been reported for the determination of atenolol and metoprolol in pharmaceutical preparations. In continuing of our
studies on the developing of simple and fast spectrofluorimetric methods for
determination of drugs and active ingredients, in this work we have developed a
spectrofluorimetric method based on the oxidation with cerium (IV) for the
determination of studied drugs in their pharmaceutical formulations.
Methods: A simple, rapid and
sensitive spectrofluorimetric method was developed for the determination of
studied drugs in pharmaceutical formulations. Proposed method is based on the
oxidation of these drugs with Ce (IV) to produce Ce (III), and its fluorescence
was monitored at 356 ± 3 nm after excitation at 254 ± 3 nm.
Results: The variables
affecting oxidation of each drug were studied and optimized. Under the
experimental conditions used, the calibration graphs were linear over the range
of 25-450, 50-550, 15-800 and 15-800 ng/mL in the case of atenolol, metoprolol,
pioglitazone and methyldopa,
respectively. The limit of detection was found to be 8.27, 16.5, 1.52 and 5.08 ng/mL
in the case of atenolol, metoprolol, pioglitazone and methyldopa, respectively. Intra- and inter-day assay precisions, expressed as the
relative standard deviation (RSD), were lower than 3% in all cases.
Conclusion: The proposed method
was applied to the determination of studied drugs in their pharmaceutical
formulations by good recoveries in the range 92-113%.