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

2013 ◽  
Vol 96 (5) ◽  
pp. 968-975 ◽  
Author(s):  
Soad S Abd El-Hay ◽  
Christa L Colyer ◽  
Wafaa S Hassan ◽  
Abdalla Shalaby

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.

2011 ◽  
Vol 8 (s1) ◽  
pp. S304-S308 ◽  
Author(s):  
V. Rajesh ◽  
V. Jagathi ◽  
K. Sindhuri ◽  
G. Devala Rao

A simple and sensitive spectrofluorimetric method has been developed for the estimation of erlotinib hydrochloride in pure and pharmaceutical dosage forms. Erlotinib hydrochloride exhibits maximum fluorescence intensity in methanol and the Beer's law was obeyed in the range of 1-5 µg/mL at an excitation wavelength (λex) of 295 nm and an emission wavelength (λem) of 339 nm. Stability studies with respect to time and temperature were also carried out. The results obtained were in good agreement with the labelled amounts of the marketed formulations. This method has been statistically evaluated and found to be accurate and precise.


Author(s):  
Hind Hadi ◽  
Mariam Jamal

Abstract A sensitive, precise and reliable indirect spectrophotometric method for the determination of chlordiazepoxide (CDE) in pure and pharmaceutical dosage forms is described. The method is based on oxidative coupling reaction between amino group resulting from acidic decomposition of CDE with phenothiazine in the presence of sodium periodate to produce an intense green soluble dye that is stable and shows a maximum absorption at 602 nm. The calibration plot indicates that Beer’s law is obeyed over the concentration range of 0.1?50 µg/mL, with a molar absorptivity of 1×104 L/mol cm and correlation coefficient of 0.9994.All the conditions that affecting on the stability and sensitivity of the formed product were studied and optimized and the suggested method was effectively applied for the determination of CDE in commercial dosage forms.


Author(s):  
Jaspreet Kaur ◽  
Daljit Kaur ◽  
Sukhmeet Singh

Objective: A simple, accurate, and selective ultraviolet-spectrophotometric method has been developed for the estimation of febuxostat in the bulk and pharmaceutical dosage forms.Method: The method was developed and validated according to International Conference on Harmonization (ICH Q2 R1) guidelines. The developed method was validated statistically with respect to linearity, range, precision, accuracy, ruggedness, limit of detection (LOD), limit of quantitation (LOQ), and recovery. Specificity of the method was demonstrated by applying different stressed conditions to drug samples such as acid hydrolysis, alkaline hydrolysis, oxidative, photolytic, and thermal degradation.Results: The study was conducted using phosphate buffer pH 6.8 and λmax was found to be 312 nm. Standard plot having a concentration range of 1–10 μg/ml showed a good linear relationship with R2=0.999. The LOD and LOQ were found to be 0.118 μg/ml and 0.595 μg/ml, respectively. Recovery and percentage relative standard deviations were found to be 100.157±0.332% and <2%, respectively.Conclusion: Proposed method was successfully applicable to the pharmaceutical formulations containing febuxostat. Thus, the developed method is found to be simple, sensitive, accurate, precise, reproducible, and economical for the determination of febuxostat in pharmaceutical dosage forms.


Author(s):  
SMITA KUMBHAR ◽  
VINOD MATOLE ◽  
YOGESH THORAT ◽  
ANITA SHEGAONKAR ◽  
AVINASH HOSMANI

Objective: A new, simple, sensitive, precise and reproducible UV visible spectrophotometric method was developed for the determination of Imatinib in pharmaceutical formulations with alizarin. Methods: The method is based on formation of yellow-colored complex. The UV spectrum of Imatinib in methanol showed λ max at 431 nm. Beer’s law is valid in the concentration range of 10-70 μg/ml. This method was validated for linearity, accuracy, precision, ruggedness and robustness. Results: The method has demonstrated excellent linearity over the range of 10-70 μg/ml with regression equation y =0.013x-0.017 and regression correlation coefficient r2= 0.997. Moreover, the method was found to be highly sensitive with LOD (4.3μg/ml) and LOQ (13.07μg/ml). Conclusion: Based on results the proposed method can be successfully applied for the assay of Imatinib in various pharmaceutical dosage forms.


2007 ◽  
Vol 90 (4) ◽  
pp. 948-956 ◽  
Author(s):  
Nahed El-Enany

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.


Author(s):  
Amir Alhaj Sakur ◽  
Bayan Balid

In this article, it has been reported new, simple, sensitive and direct spectrophotometric methods for the determination of Perindopril Erbumine (PPE) and Enalapril Maleate (ENL) in pure and in pharmaceutical forms. Spectrophotometric methods are based on the formation of yellow colored ion-pair complexes between PPE, ENL and sulphonphthalein acid dye, Bromocresol green (BCG) into chloroform were measured at the wavelength of 414 and 415nm for PPE and ENL, respectively. The optimal analytical conditions were determined. The obtained complexes (BCG: PPE) and (BCG: ENL) reached maximum absorbance directly after formation at room temperature for a stability period of 24 h. Beer’s law were obeyed in the concentration ranges of (2-20)µg/mL for PPE and (8- 44)µg/mL for ENL, the limit of detection of 0.125μg/mL and 0.230μg/mL were found for PPE and ENL, respectively. The molar absorptivity coefficients were 4.4045*104 L.moL-1.cm-1 for PPE and 1,9330*104 L.moL-1.cm-1 for ENL. The stoichiometry of the complexes formed between PPE, ENL and BCG were 1:1. No interference was observed from common excipients occurred in pharmaceutical formulations and the proposed methods have been successfully applied to determine the PPE and ENL in some pharmaceutical products and in ENL combination dosage forms with hydrochlorothiazide (HCTZ). The proposed methods were successfully validated to be utilized in the quantitative analysis of PPE and ENL in their pure and pharmaceutical products. A good agreement between the developed spectrophotometric methods with the results obtained from official reference methods for the determination of the two drugs in some real samples demonstrate that the proposed methods were suitable to quantify PPE and ENL in pharmaceutical formulations.


2008 ◽  
Vol 3 ◽  
pp. ACI.S643 ◽  
Author(s):  
Nafisur Rahman ◽  
Sk Manirul Haque

Four simple, rapid and sensitive spectrophotometric methods have been proposed for the determination of enalapril maleate in pharmaceutical formulations. The first method is based on the reaction of carboxylic acid group of enalapril maleate with a mixture of potassium iodate (KIO3) and iodide (KI) to form yellow colored product in aqueous medium at 25 ± 1°C. The reaction is followed spectrophotometrically by measuring the absorbance at 352 nm. The second, third and fourth methods are based on the charge transfer complexation reaction of the drug with p-chloranilic acid (pCA) in 1, 4-dioxan-methanol medium, 2, 3-dichloro 5, 6-dicyano 1, 4-benzoquinone (DDQ) in acetonitrile-1,4 dioxane medium and iodine in acetonitrile-dichloromethane medium. Under optimized experimental conditions, Beer's law is obeyed in the concentration ranges of 2.5-50, 20-560, 5-75 and 10-200 µg mL-1, respectively. All the methods have been applied to the determination of enalapril maleate in pharmaceutical dosage forms. Results of analysis are validated statistically.


2002 ◽  
Vol 70 (1) ◽  
pp. 67-76 ◽  
Author(s):  
EI-Adl Sobhy M. ◽  
Saleh Hanaa M.

Three accurate methods were developed for the quantitative determination of cefprozil in pure form and in its dosage forms. The first method was based upon the interaction of the drug with 3-methyl-benzothiazolinone-2-hydrazone (MBTH) in the presence of ceric ammonium sulfate or ferric chloride as an oxidizing agent, where the formed color was measured at λ 521 nm or 624 nm, respectively. The second inethod was based on the chelate formation with palladium (II) chloride (PdCl2) in the presence of buffered medium, where the formed complex was determined at λ 345 nm. The third method was based upon the reaction of the neutral solution of the hydrolysis product of drug with each of silver nitrate & lead acetate standard solutions, forming drug-metal complex and the metal ion contents were determined directly or indirectly by atomic absorption spectroscopy (AAS). The reaction conditions of the proposed methods were studied and optimized. The precision of the proposed methods was achieved by determining different samples of bulk powder and pharmaceutical dosage forms. The validity of the methods was assessed by applying the standard addition technique and the results were compared with those obtained by the reference method showing a great agreement


Author(s):  
D. K. Sharma ◽  
Jasvir Singh ◽  
Pushap Raj

Objective: A new spectrophotometric method for the determination of propranolol hydrochloride (PRO) and metoprolol tartrate (MTP), beta blocker drugs, has been developed for their analysis in pharmaceutical dosage forms for the purpose of quality control and water samples for monitoring impact on environmental water quality of natural sources and in biological fluids for ascertaining their physiological performance.Methods: The method is based on the derivatization of the amino function present in these drugs to the corresponding yellow copper (I) drug dithiocarbamate derivative through reaction with carbon disulphide, pyridine and copper (I) perchlorate in aqueous acetonitrile and measuring absorbance at 406 nm for propranolol and 400 nm for metoprolol. The different experimental parameters affecting the development and stability of the colour were carefully studied and optimized.Results: The Beer’s law is obeyed in the range of 1.0-40.0 μg/ml of each drug solution with a correlation coefficient 0.999. The maximum relative standard deviations (RSDs) in the analysis of pure PRO and MTP were 1.01 and 1.52 % respectively. The recoveries of the drugs from pharmaceutical formulations, spiked water samples and biological fluids were in the range 98.0-100.5 % with RSDs in the range 0.23-1.94% indicating good accuracy and precision of the method.Conclusion: The instantaneous development of colour and its stability, well-established stoichiometry of the reaction and above simplicity and rapidity of procedures are some special attributes of the proposed method.


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