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Determination of Labetalol Hydrochloride in Drug Formulations by Spectrophotometry
Author(s) -
Rahman Nafisur,
Rahman Habibur,
Azmi Syed Najmul Hejaz
Publication year - 2007
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.200700028
Subject(s) - chemistry , molar absorptivity , absorbance , spectrophotometry , chromatography , correlation coefficient , dosage form , labetalol , accuracy and precision , detection limit , analytical chemistry (journal) , mathematics , medicine , physics , statistics , blood pressure , optics , radiology
A validated, selective and sensitive spectrophotometric method has been developed for the determination of labetalol hydrochloride in commercial dosage forms. The method is based on the coupling reaction of positive diazonium ion of 4‐aminobenzenesulfonic acid with phenolate ion of labetalol to form a colored azo compound which absorbs maximally at 395 nm. Under the optimized experimental conditions, the color is stable up to 2 h and Beer's law is obeyed in the concentration range of 0.8–17.6 μg mL −1 with a linear regression equation of A = 4.84 × 10 −4 + 7.864 × 10 −2 C and coefficient of correlation, r = 0.9999. The molar absorptivity and Sandell's sensitivity are found to be 2.874 × 10 4 L mol −1 cm −1 and 0.013 μg cm −2 per 0.001‐absorbance unit, respectively. The limits of detection and quantitation of the proposed method are 0.08 and 0.23 μg mL −1 , respectively. The intra‐day and inter‐day precision variation and accuracy of the proposed method is acceptable with low values of standard analytical error. The recovery results obtained by the proposed method in drug formulations are acceptable with mean percent recovery ± RSD of 99.97 ± 0.52 ‐ 100.03 ± 0.63%. The results of the proposed method compared with those of Bilal's spectrophotometric method indicated excellent agreement with acceptable true bias of all samples within ± 2.0%.