Micellar Enhanced Spectrofluorometric Determination of Labetalol Through Complexation with Aluminium(III): Application to Dosage Forms and Biological Fluids

Abstract Two simple, sensitive, and specific spectrofluorometric procedures have been developed for the determination of labetalol (LBT) in pharmaceuticals and biological fluids. LBT was found to react with Al3+ , both in acetate buffer of pH 4.5 (Procedure I) and borate buffer of pH 8.0 (Procedure II), to produce highly fluorescent stable complexes. The fluorescence intensity could be enhanced by the addition of sodium dodecyl sulfate, resulting in 3.5- and 2.7-fold increases in the fluorescence intensity for Procedures I and II, respectively. In both procedures, the fluorescence intensity was measured at 408 nm after excitation at 320 nm. The different experimental parameters affecting the development and stability of the fluorescent products were carefully studied and optimized. The fluorescence intensity-concentration plots were rectilinear over the range of 0.020.1 and 0.010.05 g/mL with a detection limit of 0.003 and 0.001 g/mL for Procedures I and II, respectively. The proposed method was successfully applied to commercial tablets containing LBT. The results were in good agreement with those obtained using a reference spectrofluorometric method. Furthermore, the method was applied for the determination of LBT in spiked human plasma, and the recovery (n = 4) was 93.30 2.62%. A proposal of the reaction pathway was postulated for Procedures I and II, respectively.

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Spectrofluorometric Determination of Fluvoxamine in Dosage Forms, Spiked Plasma, and Real Human Plasma by Derivatization with Fluorescamine

Journal of AOAC International ◽

10.1093/jaoac/90.2.376 ◽

2007 ◽

Vol 90 (2) ◽

pp. 376-383 ◽

Cited By ~ 11

Author(s):

Nahed El-Enany

Keyword(s):

Human Plasma ◽

Reaction Pathway ◽

Biological Fluids ◽

Pharmaceutical Formulations ◽

Dosage Forms ◽

Spectrofluorometric Determination ◽

Spiked Plasma ◽

Experimental Parameters ◽

Good Agreement

Abstract A sensitive, simple, and selective spectrofluorometric method was developed for the determination of fluvoxamine (FXM) in pharmaceutical formulations and biological fluids. The method is based upon the reaction between the drug and fluorescamine in borate buffer of pH 8.0 to yield a highly fluorescent derivative that is measured at 481 nm after excitation at 383 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The method was applied for the determination of the drug over the concentration range of 0.11.1 μg/mL with a detection limit of 0.01 μg/mL (2 10-8 M). The proposed method was successfully applied to the analysis of commercial tablets. The results obtained were in good agreement with those obtained using a reported spectrophotometric method. The method was applied for the determination of FXM in spiked human plasma with recovery (n = 4) of 97.32 1.23%, while that in real human plasma (n = 3) was 90.79 2.73%. A proposal for the reaction pathway is presented.

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Spectrofluorometric determination of nicardipine, nifedipine and isradipine in pharmaceutical preparations and biological fluids

Open Chemistry ◽

10.2478/s11532-008-0011-x ◽

2008 ◽

Vol 6 (2) ◽

pp. 222-228 ◽

Cited By ~ 10

Author(s):

Sheikha Al-Ghannam ◽

Abeer Al-Olyan

Keyword(s):

Fluorescence Intensity ◽

Reaction Pathway ◽

Biological Fluids ◽

Sodium Dodecyl ◽

Pharmaceutical Preparations ◽

Reduction Reaction ◽

Factors Affecting ◽

Plasma And Urine Samples

AbstractA simple and highly sensitive spectrofluorometric method was developed for the determination of some 1,4-dihydropyridine compounds namely, nicardipine, nifedipine and isradipine in pharmaceutical preparations and biological fluids. The method is based on the reduction of nicardipine, nifedipine and isradipine with Zn/HCl and measuring the fluorescence intensity obtained (λem/λex) at 460/364, 450/393 and 446/360 nm, respectively. The factors affecting the development of the fluorophore and its stability were studied and optimized. The effect of some surfactants such as β-cyclodextrin (βCD), carboxymethylcelullose (CMC), sodium dodecyl sulphate (SDS) and triton X-100, on the fluorescence intensity was studied. The fluorescence intensity-concentration plots of nicardipine, nifedipine and isradipine were rectilinear over the ranges 0.4–6.0, 0.2–4.0 and 0.1–9.0 μg ml−1 with detection limits of 0.0028, 0.017 and 0.016 μg ml−1, respectively. The proposed method was successfully applied to commercial tablets containing the compounds; the percentage recovery agreed well with those obtained using the official methods. The method was further extended to the in vitro determination of the compounds in spiked human plasma and urine samples. A proposal of the reduction reaction pathway was postulated.

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Spectrofluorimetric and Spectrophotometric Determination of Gliclazide in Pharmaceuticals by Derivatization with 4-Chloro-7-nitrobenzo-2-oxa-1,3-diazole

Journal of AOAC International ◽

10.1093/jaoac/86.2.209 ◽

2003 ◽

Vol 86 (2) ◽

pp. 209-214 ◽

Cited By ~ 11

Author(s):

Nahed El-Enany

Keyword(s):

Reaction Pathway ◽

Biological Fluids ◽

Coupling Reaction ◽

Pharmaceutical Formulations ◽

Signal To Noise ◽

Yellow Fluorescence ◽

Spectrophotometric Methods ◽

Experimental Parameters ◽

Good Agreement

Abstract Accurate, sensitive, and simple spectrophotometric and spectrofluorimetric methods were developed for the determination of gliclazide in pharmaceutical formulations and biological fluids. Both methods are based on a coupling reaction between gliclazide and 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole in borate buffer, pH 7.8, in which a yellow reaction product that can be measured spectrophotometrically at 400 nm was developed. The same product exhibited a yellow fluorescence at 470 nm upon excitation at 400 nm. The absorbance–concentration plot was rectilinear over the range of 2–20 μg/mL with minimum detectability [signal-to-noise (S/N) ratio = 2] of 0.2 μg/mL (6.18 × 10−7 M); the fluorescence–concentration plot was rectilinear over the range of 0.2–2.5 μg/mL with minimum detectability (S/N = 2) of 0.02 μg/mL (6.18 × 10−8M). The different experimental parameters affecting the development and stability of the color were carefully studied and optimized. Both methods were successfully applied to the analysis of commercial tablets. The results were in good agreement with those obtained with the official and reference spectrophotometric methods. A proposal of the reaction pathway was presented.

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Stability-Indicating Micelle-Enhanced Spectrofluorimetric Method For Determination of Tamsulosin Hydrochloride In Dosage Forms.

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v11i2.6692 ◽

2015 ◽

Vol 11 (2) ◽

pp. 3513-3531 ◽

Cited By ~ 1

Author(s):

Mona Elsayed Elshahed ◽

Ibrahim Habib

Keyword(s):

Fluorescence Intensity ◽

Sodium Dodecyl ◽

Pharmaceutical Formulations ◽

Official Method ◽

Forced Degradation ◽

Ich Guidelines ◽

Spectrofluorimetric Method ◽

Highly Sensitive ◽

Good Agreement

A rapid, simple and highly sensitive spectrofluorimetric method is developed for the determination of Tamsulosin hydrochloride (Tams.HCl) in pharmaceutical formulations. The proposed method is based on investigation of the fluorescence spectral behavior of Tams.HCl in a sodium dodecyl sulphate (SDS) micellar system. In aqueous solution of Tris buffer of pH 7±0.2, SDS causes marked enhancement in the fluorescence intensity of Tams.HCl (about +110%). The fluorescence intensity is measured at 328 nm after excitation at 280 nm and the fluorescence-concentration plots are rectilinear over the range 0.1-1.2 µg ml-1, with lower detection limit of 0.027 µg ml-1 and quantification limit of 0.09 µg ml-1. The method is successfully applied to the analysis of the studied drug in its commercial capsules, and the results are in good agreement with those obtained with the official method. The application of the proposed method is extended to stability studies of Tamsulosin hydrochloride after exposure to different forced degradation conditions, such as acidic, alkaline and oxidative conditions, according to ICH guidelines.

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Determination of Phenolic Sympathomimetic Drugs in Pharmaceutical Samples and Biological Fluids by Flow-Injection Chemiluminescence

Journal of AOAC International ◽

10.1093/jaoac/83.6.1299 ◽

2000 ◽

Vol 83 (6) ◽

pp. 1299-1305 ◽

Cited By ~ 7

Author(s):

Fatma A Aly ◽

Salma A Al-Tamimi ◽

Abdulrahman A Alwarthan

Keyword(s):

Formic Acid ◽

Flow Injection ◽

Reaction Pathway ◽

Biological Fluids ◽

Dosage Forms ◽

Pharmaceutical Samples ◽

Sympathomimetic Drugs ◽

Highly Sensitive ◽

Flow Injection Chemiluminescence

Abstract A rapid and highly sensitive flow-injection chemiluminometric method was developed for determination of 3 sympathomimetic drugs, namely, etilefrine hydrochloride, isoxsuprine hydrochloride, and prenalterol hydrochloride. The method is based on chemiluminescence induced by oxidation of drugs with acidified potassium permanganate in the presence of formic acid as a carrier. The calibration graphs were linear over the concentration ranges 0.2–9, 0.2–12.5, and 0.025–1.25 μg/mL for the 3 compounds, respectively. The method was applied successfully in determining the drugs in dosage forms and in biological fluids. A proposal for the reaction pathway is suggested.

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Spectrofluorometric Determination of Olanzapine and Fluphenazine Hydrochloride in Pharmaceutical Preparations and Human Plasma Using Eosin: Application to Stability Studies

Journal of AOAC International ◽

10.1093/jaoac/91.6.1309 ◽

2008 ◽

Vol 91 (6) ◽

pp. 1309-1317 ◽

Cited By ~ 11

Author(s):

Fathalla Belal ◽

Amina El-Brashy ◽

Nahed El-Enany ◽

Nihal El-Bahay

Keyword(s):

Human Plasma ◽

Reaction Pathway ◽

Pharmaceutical Preparations ◽

Stability Studies ◽

Quenching Effect ◽

Spectrofluorometric Determination ◽

The Mean ◽

Kinetics Of ◽

Good Agreement

Abstract A simple, rapid, and sensitive spectrofluorometric method has been developed for the determination of olanzapine (OLZ) and fluphenazine hydrochloride (FPZ HCl). The proposed method is based on the quantitative quenching effect of the studied drugs on the native fluorescence of eosin at pH 3.4 and 3.2 for OLZ and FPZ HCl, respectively. The fluorescence was measured at 547 nm after excitation at 323 nm. The fluorescence-concentration plots were rectilinear over the range of 0.051.0 and 0.101.0 g/mL, with lower detection limits of 1.8 103 and 1.2 103 g/mL, for OLZ and FPZ HCl, respectively. The proposed method was successfully applied to the analysis of commercial tablets and ampules containing the drugs, and the results were in good agreement with those obtained with reference methods. The proposed method was further applied to the determination of OLZ in spiked human plasma. The mean recovery was 98.62 0.24 (n 4). The method was also used for stability studies of FPZ HCl upon oxidation with hydrogen peroxide, and the kinetics of the reaction were studied. A proposal for the reaction pathway was postulated.

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Utility of 4-Chloro-7-Nitrobenzofurazan (NBD-Cl) for the Spectrophotometric and Spectrofluorometric Determination of Several Antihistamine and Antihypertensive Drugs

Journal of AOAC International ◽

10.5740/jaoac.11-246 ◽

2013 ◽

Vol 96 (5) ◽

pp. 968-975 ◽

Cited By ~ 1

Author(s):

Soad S Abd El-Hay ◽

Christa L Colyer ◽

Wafaa S Hassan ◽

Abdalla Shalaby

Keyword(s):

Fluorescence Intensity ◽

Drug Concentration ◽

Antihypertensive Drugs ◽

Pharmaceutical Formulations ◽

Dosage Forms ◽

Emission Wavelength ◽

Pharmaceutical Dosage Forms ◽

Spectrofluorometric Determination ◽

Highly Sensitive

Abstract New, sensitive, and selective spectrophotometric and spectrofluorometric methods have been developed for determination of clemastine hydrogen fumarate (Clem), loratadine (Lor), losartan potassium (Los), and ramipril (Ram) in both pure form and pharmaceutical formulations using 4-chloro-7-nitrobenzofurazan (NBD-Cl), which is a highly sensitive chromogenic and fluorogenic reagent. The relation between absorbance at 470, 467, 471, and 469 nm and the concentration was linear over the ranges 5–35, 10–100, 10–90, and 10–120 μg/mL for Clem, Lor, Los, and Ram, respectively. The complexation products were also measured spectrofluorometrically at the emission wavelength 535 nm for Clem, Lor, and Ram and at 538 nm for Los with excitation at 477 and 452 nm for Clem and Lor, respectively, and 460 nm for both Los and Ram. The fluorescence intensity was directly proportional to the drug concentration over the ranges 0.05–0.5, 5–20, 1–6, and 2–15 μg/mL for Clem, Lor, Los, and Ram, respectively. The methods were successfully applied for the determination of the studied drugs in pharmaceutical dosage forms with excellent recovery.

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