Determination of Labetalol Hydrochloride in Drug Formulations by Spectrophotometry

Abstract

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 mg 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 mg cm -2 per 0.001-absorbance unit, respectively. The limits of detection and quantitation of the proposed method are 0.08 and 0.23 mg 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%.

Rapid and Simple Spectrophotometric Analysis of Labetalol Hydrochloride in Pharmaceutical, Urine and Blood Samples

“…UV-Visible spectrophotometry is the technique of choice even today in the third world countries due to its low cost, ease of operation, high sensitivity, and simplicity of the instrumentation used for the technique. Several spectrophotometric methods based on the reaction of LBT with sodium nitroprusside and hydroxylamine hydrochloride [20], p-N,N-dimethylphenylenediamine hydrochloride [21], suprachen violet 3 B [21], diazotized 4-aminobenzene sulfonic acid [22], potassium permanganate [23], diazotized benzocaine in presence of trimethylamine or diazotized p-nitroaniline in the presence of sodium carbonate [24], and ferric 1, 10phenanthroline [25 ] have been developed to determine the concentration of LBT in bulk drug and pharmaceutical formulations effectively. Among these, only diazotized based method has been used to analyze LBT in biological samples [24].…”

A Novel Spectrophotometric Method for the Determination of Levodopa with the Detection System of Potassium Ferricyanide‐Fe(III)

“…At present, different methods to determine levodopa have been employed: high-performance liquid chromatography, 4 fluorescence spectrometry, 5 electrochemistry method, 6 chemiluminescence, 7 flow injection analysis, 8,9 and several others. 6 Compared with the methods mentioned above, 4-11 as the same as literature [18][19][20] concerning pharmaceutical analysis by spectrophtometry, this proposed method has high sensitivity, low detection limit, simple operation as well as low cost. [12][13][14] Due to its oxidability, potassium ferricyanide also plays an important role in chemiluminescence.…”

Spectrofluorimetric Determination of Labetalol Hydrochloride in Pharmaceutical Preparations and Urine Samples

“…The therapeutic importance of the drug has engendered development of assays for its quantitation in commercial dosage forms and biological fluids. A literature survey revealed that analytical techniques including spectrophotometry (3)(4)(5), HPLC (6)(7)(8)(9), HPLC-MS (10), micellar liquid chromatography (11), capillary liquid chromatography (12) capillary electrophoresis (13)(14), capillary isotachophoresis (15) and NMR spectroscopy (16) have been employed for the determination of LBT. LBT was also analyzed in pharmaceutical preparations using an ion-selective electrode method (17).…”