scholarly journals Spectrofluorimetric determination of carvedilol in dosage form and spiked human plasma through derivatization with 1-dimethylaminonaphthalene-5-sulphonyl chloride

2010 ◽  
Vol 16 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Fattah El-Sayed ◽  
Taghreed Mohamed ◽  
Anwer Taha
Keyword(s):  
Human Plasma ◽  
Reaction Pathway ◽  
Biological Fluid ◽  
Spiked Human Plasma ◽  
Spectrofluorimetric Method ◽  
Limit Of Quantitation ◽  
Spectrofluorimetric Determination ◽  
Yield Formation ◽  
Good Agreement

A sensitive, simple and selective spectrofluorimetric method was developed for the determination of carvedilol (CA) in pharmaceutical formulation and a biological fluid. The method is based on the reaction between the drug and 1-dimethylaminonaphthalene- 5-sulphonyl chloride (dansyl chloride) in the presence of mixture (acetone:0.5 M sodium carbonate, 3:2) at pH 10 to yield a highly fluorescent derivative that is measured at 445 nm after excitation at 350 nm. Different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence concentration plot was rectilinear over the range of 5.0-80.0 ng ml-1 with a lower detection limit (LOD) of 1.90 ng ml-1 and the limit of quantitation (LOQ) of 5.15 ng ml-1. Quantum yield, formation constant (K) and free energy change (?G) values were calculated. The proposed method was successfully applied to the analysis of commercial tablets. The results obtained were in good agreement with those obtained using the official titrimetric method [1,2]. Furthermore, the method was applied for the determination of CA in spiked human plasma, the mean % recovery (n = 5) is 97.82?0.373. A proposal of the reaction pathway was presented.

scholarly journals Spectrofluorimetric Determination of Warfarin Sodium by Using N1-Methylnicotinamide Chloride as a Fluorigenic Agent

2005 ◽  
Vol 88 (2) ◽  
pp. 455-461 ◽  
Author(s):  
Mohamed A El Dawy ◽  
Mokhtar M Mabrouk ◽  
Riad A El Barbary
Keyword(s):  
Aqueous Solutions ◽  
Human Plasma ◽  
Plasma Samples ◽  
Spiked Human Plasma ◽  
Human Plasma Samples ◽  
Warfarin Sodium ◽  
Spectrofluorimetric Method ◽  
Spectrofluorimetric Determination ◽  
Methylene Groups

Abstract A spectrofluorimetric method is described for the determination of drugs containing active methylene groups adjacent to carbonyl groups. The method was applied successfully to the determination of warfarin sodium in laboratory-prepared mixtures, in commercial tablets, and in spiked human plasma samples. Finally, the method was applied to the determination of the steady-state concentration of warfarin sodium in the blood of a hospitalized patient. The method involves the reaction of warfarin sodium with 0.2 ml (0.4 × 10−3M) N1-methylnicotinamide chloride reagent in the presence of 3 mL 1.0N NaOH and cooling in ice for 8 min, followed by adjustment of the pH to 2.0, using formic acid and heating for 4 min, whereby a highly fluorescent reaction product is produced. The optimal wavelengths of excitation and emission were determined by using a synchronous wavelength search and found to be 284 and 354 nm, respectively. The standard curves were linear over a concentration range of 50–1500 ng/mL in both aqueous solutions and spiked human plasma samples. The mean recoveries (± standard deviation) were 101.157 (±1.33) and 95.73 (±1.88%) for aqueous solutions and spiked human plasma samples, respectively. The method showed good specificity and precision. The proposed method is simple and economical because of its minimal instrumentation and chemicals requirements. Nevertheless, it is highly sensitive, specific, and reproducible. Accordingly, it is suitable for quality-control applications, drug monitoring, and bioavailability and bioequivalency studies.

scholarly journals Spectrofluorimetric determination of amlodipine in human plasma without derivatization

2012 ◽  
Vol 48 (4) ◽  
pp. 719-725 ◽  
Author(s):  
Yucel Kadioglu ◽  
Murat Ozturk
Keyword(s):  
Channel Blocker ◽  
Limit Of Detection ◽  
Plasma Samples ◽  
Experimental Conditions ◽  
Spectrofluorimetric Method ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Spectrofluorimetric Determination ◽  
Better Than

A rapid and sensitive spectrofluorimetric method was developed for the determination of amlodipine (AD), a calcium channel blocker, in the plasma. The type of solvent, the wavelength range, and the range of AD concentration were selected to optimize the experimental conditions. The calibration curves were linear (r² >0.997) in the concentration range of 0.1-12.5 ppm of AD. The limit of quantitation and limit of detection values for the method for plasma samples were 0.1 ppm and 0.07 ppm, respectively. The precision calculated as the relative standard deviation was less than 3.5%, and the accuracy (relative error) was better than 5.5% (n=6). The method developed in this study can be directly and easily applied for the determination of AD in the plasma without derivatization in plasma.

scholarly journals Bioanalytical Method Development and Validation for the Determination of Favipiravir in Spiked Human Plasma by using RP-HPLC

2021 ◽  
pp. 275-281
Author(s):  
Pallavi V. Duse ◽  
Kamalkishor G. Baheti
Keyword(s):  
Human Plasma ◽  
Hplc Method ◽  
Therapeutic Drug ◽  
Pharmacokinetic Studies ◽  
Gradient System ◽  
Spiked Human Plasma ◽  
Rp Hplc ◽  
Relative Standard ◽  
Limit Of Quantitation

A precise, simple and reproducible reverse phase liquid chromatography (RP-HPLC) method was developed and validated for determination of Favipiravir by using Carbamazepine as internal standard in spiked human plasma. A chromatographic separation was accomplished with Cromasil C18 (250mm x 4.6ID, Particle size: 5 micron) column using mobile phase consists of methanol: water in the ratio (35:65, %v/v), at pH 3.0 with binary gradient system-maintained flow rate at 0.8ml/min. The detection wavelength of drug sample was at 225 nm. Extraction was done by using ethyl acetate as extracting solvent. The retention time of Favipiravir was found to be 6.62 min.  The method was found to be linear in the concentration range of 0.2-3.2 µg/ml. Limit of quantitation (LOQ) value was found to be 0.72. The intra- and inter day precision and accuracy lies within the specified range. The recovery studies were found to be in the range of 97.6 to 100.2%. %Relative standard deviation (RSD) was found to be in the range of 0.07-2.80%. All parameters were found to be validated from spiked human plasma. The proposed RP-HPLC method is highly accurate and rapid for the determination of favipiravir in human plasma and can be applied for pharmacokinetic studies and Therapeutic drug monitoring.

scholarly journals Kinetic Spectrophotometric Determination of Josamycin in Formulations and Spiked Human Plasma Using 3-Methylbenzothiazolin-2-one Hydrazone/Fe+3 System

2004 ◽  
Vol 87 (2) ◽  
pp. 352-359 ◽  
Author(s):  
Abdulrahman A Al-Majed ◽  
Fathalla Belal ◽  
Nasr Y Khalil ◽  
Kamal E E Ibrahim
Keyword(s):  
Human Plasma ◽  
Reaction Pathway ◽  
Fixed Time ◽  
Chloride System ◽  
Spiked Human Plasma ◽  
Fixed Concentration ◽  
Kinetic Spectrophotometric ◽  
Calibration Equations

Abstract A simple kinetic spectrophotometric method was developed for the determination of josamycin in its dosage forms and spiked human plasma. The method is based on reaction of the drug with 3-methylbenzothiazolin-2-one hydrazone/ferric chloride system for a fixed time of 20 min at 70°C and measuring the produced color at 665 nm. The absorbance-concentration plot is rectilinear over the range of 5.0–30.0 μg/mL with detection limit of 1.0 μg/mL (1.2 × 10−6M). The determination of josamycin by the fixed concentration and the rate-constant methods is also feasible with the calibration equations obtained, but the fixed-time method proved to be more applicable. The procedure was successfully applied to commercial tablets. The results obtained were favorably compared with those given by reference methods. The method was further extended to the in vitro determination of josamycin in spiked human plasma. The recovery (n = 8) was 100.76 ± 3.43%. The stoichiometry of the reaction between the drug and the reagent was studied by adopting the limiting logarithmic method, and a proposal of the reaction pathway was presented.

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