Sensitive Spectrophotometric Method Research Articles

Spectrophotometric Determination of Lisinopril Drug by Oxidative Coupling Reaction with 4-aminonaphthalene-1- sulfonic acid Reagent

A simple, rapid and sensitive spectrophotometric method for determination of Lisinopril (LS) in both pure form and pharmaceutical preparations has been reported. The adapted technique based on utilization 4-aminonaphthalene-1-sulfonic acid as a Chromogenic reagent through an oxidative coupling reaction with Lisinopril and Potassium Peroxydisulfate (oxidation agent) in acidic medium to form green dye soluble product absorption maxima at 612 nm. Linearity was in the range 2–43 μg ml-1. The values of molar absorption coefficient (ε), correlation coefficient and Sandel’s index were found to be 10.3808 × 103 L. mole-1 cm-1, 0.9995 and 0.00343 µg.cm-2 respectively. The average of recovery % was 100.067. Detection Limit and quantitative limit were 0.0343 µg/ml and 0.1143 µg/ml. The proposed method has been successfully applied in the determination of preparations containing lisinopril.

Sử dụng hiện tượng cộng hưởng plasmon bề mặt của dung dịch nano vàng để xác định amikacin trong mẫu dược phẩm bằng phương pháp quang học

A simple and highly sensitive spectrophotometric method for detecting amikacin was developed based on the change in surface plasmon resonance (SPR) properties of gold nanoparticles (AuNPs). The change in the AuNPs solution colour from red to blue in the presence of trace amounts of amikacin makes the method visible to the naked eye. Furthermore, with the addition of amikacin, in the UV-Vis spectrum appears another absorption band at 650 nm, and the AuNPs solution also gave a linear increase of optical absorption ratio A650/A520 with a logarithm of amikacin concentration in the range of 3 × 10-7 - 3.5 × 10-6 M. Under the optimum conditions, including 2.5 × 10-4 M gold nanoparticles solution, pH = 6 and 2 mM NaCl with an incubation time of 4 minutes, the proposed method achieved the low limit of detection (LOD) of 7.2 × 10-8 M, the limit of quantitation (LOQ) of 2.4 × 10-7 M, high precision (RSD < 5%). Therefore, the developed method can be applied to determine amikacin in pharmaceutical samples and in plasma and urine samples.

Estimation of Furosemide Spectrophotometrically in Pharmaceutical preparations by Oxidative Coupling Reaction

A simple, rapid and sensitive spectrophotometric method was described for the determination of Furosemide (FUR). The method is based on the oxidative coupling reaction between Furosemide and 1-Naphthylamine-4-sulfonic acid in the presence of potassium permanganate to form a yellow colored product with maximum absorptions at 465nm, which is soluble in water. Beer's law is obeyed in the concentration range of 3 to 23㎍.ml-1 with a molar absorptivity of 1.065×104 L.mol-1.cm-1, and Sandell's sensitivity of 0.0310㎍.cm-2, respectively. The correlation coefficient of 0.9994, with recovery average % of 99.948. Limit of detection (LOD), limit of quantification (LOQ) of 0.971㎍.ml- 1 and 3.237 ㎍.ml -1 and a relative standard deviation (RSD) % of 0.641 to 0.812. The proposed method has been used to successfully determine furosemide in pharmaceutical formulations (Tablet).

Solid Phase Extraction-Spectrophotometric Determination Of Isoxsuprine Hydrochloride In Different Samples Using Modified Magnetic Nanoparticales

A green, simple and sensitive spectrophotometric method was proposed for the determination of isoxsuprine hydrochloride (ISX), based on the preconcentration with cetyltrimethylammonium bromide (CTAB) modified magnetic iron oxide nanoparticales (MNPs). ISX was coupled with diazotized metoclopramide drug via diazotization-coupling reaction in alkaline medium to form yellow-orange color product which was extracted and measured spectrophotometrically at λmax444 nm. Various parameters affecting the azo-dye removal by adsorption on modified magnetic nanoparticales (Fe3O4@CTAB) such as pH of solution, volume of diazotized reagent, volume of surfactant, amount of adsorbent and type of desorbing solvent were studied. The linear calibration graph were obtained in the concentration range of 0.3-7.0 µg/mL of ISX, the limit of detection and the limit of quantification calculated to be 0.29and 0.99µg/mL, respectively. Accuracy and precision described by relative standard deviation and relative recovery percentages. The results obtained show that the CTAB-coated MNPs could be employed in the extraction of the drug in the azo dye form from different samples. The ISX was extracted successfully in pharmaceutical forms and spiked samples of river water.

Spectrophotometric Determination Of Anti-Ulcer Drug (Cimetidine) By 2.4-Dinitrophenylhydrazine Reagent

An innovative, simple, and sensitive spectrophotometric method was described for the determination of cimetidine in both its pureform and in pharmaceutical formulations. By oxidizing 2.4-dinitrophenylhydrazine (2.4-DNPH) and mixing it with cimetidine in analkaline solution, a brightly colored chromogen with a maximum absorption wavelength of 586 nm is created. After that,spectrophotometry was used to quantify the amount of cimetidine. Other analytical criteria, such as the ideal reaction circumstances,were evaluated. These criteria included variables like the volumes of 2.4-DNPH and potassium iodate, the amount of base, thecoupling reaction time, temperature, and the order in which the constituents of the final product are added. Beer's law is applied toconcentrations of (25–250) µg/mL-1 with correlation coefficient (R2) = 0.9964, molar absorptivity 353.276 (L.mol-1.cm-1), andSandell's law. The recommended method for locating cimetidine in pharmaceutical formulations worked well.

Spectrophotometric Determination of Sulfathiazole in Different Pharmaceutical Formulations

A simple, rapid and sensitive spectrophotometric method for the determination of sulfathiazole in aqueous solution is described. The method is based on the diazotized coupling reaction of aniline with sulfathiazole drugs. A mixture of an acidic solution (hydrochloric acid) of the sulfathiazole and the chromogenic was treated with sodium nitrite and aniline to form an intense orange water-soluble dye that is stable and has a maximum absorption at 480 nm. It was observed that the method is applicable for the determination of sulfathiazole in Nicotrim, Contri, Biotran and Bactrim forte formulations. The LOD ( limit of detection) and LOQ ( limit of quantification) for the method were calculated and found to be 0.23 and 0.48 ppm respectively.

Use of Mesalazine for the Determination of Dopamine and Its Pharmaceutical Preparations by Spectrophotometric Method

A sensitive spectrophotometric method was used for the determination of Dopamine (DM) in a basic medium via its oxidative coupling by Mesalazine (MES), which was exploited as a reagent and Na2S2O8 as an oxidizing agent, the measurement was at a wavelength of 522 nm. The proposed method was successfully applied for the determination of dopamine (DM) in the pharmaceutical preparation (ampules). It was valid within a concentration range of 2.7 31.25 -1 and the linear regression was R2 = 0.9977. The important analytical parameter include: molar absorptivity (0.45x104 l.mol1.cm-1), the Sandell's sensitivity index (0.03343 µg/cm2), limit of detection (LOD) and limit of quantification (LOQ) were (0.37 and 1.23 µg.ml-1), respectively. It also succeeded in giving acceptable ttest values.

Utility of 2,2׳- Bipyridyl Reagent in Spectrophotometric Assay of Acetylcysteine in Pure Form and in Its Pharmaceutical Preparations

This study includes development of a sensitive spectrophotometric method for the determination of acetylcysteine in aqueous solution. The method is based on the oxidation of acetylcysteine with a ferric ion, followed by reacting of produced ferrous ion with 2,2׳-bipyridyl to form a pink complex , which is stable and water-soluble and has the highest absorption at a wavelength of 524 nm. The limits of Beer's law were in the concentration range of (5-180) µg of acetylcysteine in a final volume of 20 milliliters (0.25-9.0 µg.ml-1) and the molar absorptivity of 8633.28 L. mol-1 .cm-1 , Sandell's sensitivity index of 0.0189 µg.cm-2. The relative error of -4.28% – 4.98 % and relative standard deviation of ± 0.56% - ± 3.75% depending on the concentration level. The limit of detection limit(LOD) and limit of quantitation (LOQ) were calculated and equal to 0.01837 and 0.06124 µg/ml respectively, no inference was observed in the common pharmaceutical excipients. The results obtain by proposed method were in good agreement with those obtain from official British pharmacopoeia using t-test (at 95% confidence limit) which indicates that there is no significant differences between them. The method was successfully applied to determine acetylcysteine in its pharmaceutical preparations.

Indirect spectroscopic determination of esomeprazole using malachite green dye in the presence of N-bromosuccinimide

A simple, fast and sensitive spectrophotometric method has been developed for the determination of esomeprazole in its pure form and also in the form of a pharmaceutical preparation. The highest absorption was found at a wavelength of 618 nm and the limits of Beer were (2_24) µg/ml. The molar absorbance (2.1070 ˣ104) L.mol-1 .cm-1, Sandell sensitivity 0.016 µg.cm-2, and limits of detection LOD 0.0153 µg/ml, LOQ 0.0510 µg/ml were determined the method was also applied to pharmaceutical preparations, and the validity of the method was confirmed by standard addition.

Spectrophotometric Determination of an Antidiabetic Drug Metformin by KMnO4 and Sulphanilic Acid Method

For the determination of Metformin, two simple and sensitive spectrophotometric methods are developed. The first method A is indirect; after allowing the reaction between KMnO4 and drug, the excess amount of KMnO4 is determined spectrophotometrically. The excess of KMnO4 was made to react with a fixed amount of methyl orange dye and the absorbance is measured at 510nm. For this method, Beer’s law is obeyed in the concentration range of 0.5- 5 μg/ml. Molar absorptivity and Sandell’s sensitivity are found to be 0.12916 x 105 L mol-1cm-1 and 0.01 μg/cm2 respectively. The second method B is based on the principle of formation of orange color as a result of reaction between drug and diazotised sulfanilic acid. The resulting solution is estimated spectrophotometrically by taking absorbance at 510 nm. Conditions of the methods are optimized by studying all the parameters that affect the stability and colour of the complex. For this method, Beer’s law is obeyed in the concentration range 1.0 - 8.0 μg /ml. Molar absorptivity and Sandell’s sensitivity are found to be 0.2583 x 104 L mol-1cm-1 and 0.05 μg/cm2 respectively. The proposed methods are appropriate for determination of metformin in pharmaceutical formulations.

Spectrophotometric Determination of Allopurinol by Oxidative Coupling Reaction Using 2-Nitrophenol Reagent in the Presence of N-Bromosuccinimide

This research included the development of a fast, easy and sensitive spectrophotometric method for the determination of quantities of allopurinol. The method depends on the oxidative coupling reaction between allopurinol and the reagent 2-nitrophenol in the presence of N-bromosuccinimide, so the product is a yellow color soluble in water that gives the highest absorption at the wavelength 420 nm and it follows Beer’s law In a range of concentrations ranged from 24-2.4 μg/ml and the molar absorbance value was 9282.02 liters. ml-1.cm-1, the value of the correlation coefficient is R = 0.9963 and the Sandell index value has 0.0146 µg/cm2, the relative standard deviation value is 1.273 RSD%, and the detection limit is 0.6635 µg/ml. The proposed method has been successfully applied in the determination of allopurinol in its preparation. Pharmacist keywords: Allopurinol, oxidative conjugation, 2-Nitrophenol

New spectrophotometric method for determination of mebendazole by oxidative coupling reaction

A rapid , simple, accurate and sensitive spectrophotometric method was developed for determination of mebendazole ( MBL ) in pure form and in its pharmaceutical dosages. This method depend on oxidation of MBL with excess amount of N-bromosuccinimide ( NBS ) in acidic medium with standing for complete the reaction , and the oxidized MBL coupled with Rhodamine B to get red product related with MBL amount and measuring the absorbance of surplus dye at 570 nm. A linear calibration curve was obtained over the concentration range 2.5 – 30 μg.ml-1 with correlation coefficient of 0.9992. The molar absorptivity and sandell's sensitivity index values were determined to be 1.476 × 104 L.mol-1.cm-1 and 0.02 μg.cm-2. The limit of detection (LOD) and quantification (LOQ) were calculated to be 0.469 and 1.982 μg.ml-1, respectively . The proposed method has been successfully applied to the determination of MBL in available dosage form, the validity proposed method was confirmed by recovery study via standard addition technique.

Spectrophotometric determination of phosphate in presence of arsenate

A simple and sensitive spectrophotometric method has been optimized for the determination of phosphate in the presence of arsenate. This method is based on the formation of phosphomolybdate complex from phosphate and added molybdate ion in an acidic medium, followed by the reduction of the complex with hydrazine hydrate. The system obeys Lambert-Beer’s law in the concentration range 60-1080 ppb. The optimized volume of different reagents was 3.5 mL of 0.25% ammonium molybdate, 1.5 mL of 0.25 N sulfuric acids, and 1 mL of 0.5 M of hydrazine hydrate. The time required for the full-color development was 15 minutes at 30oC. The arsenate interference was successfully removed by using sodium thiosulphate and sodium metabisulfite below the arsenic concentration of 100 ppb. 0.2 mL of 1 M sodium metabisulfite and 1 mL of 0.1 M sodium thiosulphate were found to be the optimum volume for inhibiting arsenate interference below 100 ppb arsenate concentration.

Different Approaches in Manipulating Ratio Spectra for Analyzing Amlodipine Besylate and Irbesartan Combination.

Hypertension is a key risk factor for ischemic heart disease and atherosclerosis. Most patients require a combination of antihypertensive medications to accomplish their therapeutic goals. Antihypertensive medicines such as calcium channel blockers and angiotensin receptor blockers are indicated for patients whose high blood pressure cannot be controlled with monotherapy. The combination of amlodipine besylate (AML) with irbesartan (IRB) is an example of this synergistic activity in lowering blood pressure. In this regard, the goal of the research is to develop sensitive spectrophotometric methods for the simultaneous determination of amlodipine besylate and irbesartan. Three simple ratio spectra-manipulating spectrophotometric methods namely, ratio difference, mean centering of ratio spectra, and derivative ratio, were developed for the simultaneous assay of the cited mixture. Linear correlations were attained over the concentration range of 1-35 μg/mL and 2-35 μg/mL for amlodipine besylate and irbesartan, respectively. The methods were validated according to the International Conference on Harmonization guidelines with good results. The methods developed were successfully applied for the assay of the cited drugs in their marketed formulation. They could be efficiently used for routine analysis of the mentioned drugs in QC laboratories. The proposed approaches do not require expensive solvents or complex instruments. They could be used in routine laboratory tests where time and cost are crucial.

Spectrophotometric Estimation of Clonazepam as Pure Form and in its Pharmaceutical Formulation (Tablet) Using Alizarin Red S

An easy and sensitive spectrophotometric method has been suggested for the assay of clonazepam (CLZM) as pure form and in its formulation as tablets. The present method based on the reaction of CLZM with alizarin red S reagent (ALRS) via proton transfer reaction to form a colored solution with a maximum absorption at wavelength of 528 nm and the optimal conditions for the reaction were studied. The linearity was within the concentration range from 1 to 30 µg/ml, with an R2 value (determination coefficient) of 0.9882 and the sensitivity express via the molar absorption of 7.04x103 l mol-1.cm-1, while Sandell's sensitivity index has been determined and equal to 0.0448 µg/ cm2.The percentage of relative standard deviation (RSD%) which express the precision of the method, percentage of relative error (RE%) express the accuracy, the LOD and LOQ also have been estimated. The application of the suggested method to the determination of CLZM in tablet gave satisfactory results.

Comparative analysis of Extraction and Determination of Inulin by Spectrophotometric and TLC methods from Indian plant sources

Inulin a versatile multifunctional polyfructan, has been employed in food industry as a low-calorie sugar and fat replacer, as a dietary fiber, as a prebiotic agent in pharmaceutical, in food formulations and in drug targeting and nanotechnology. The growing need and application of plant-based natural products like inulin in food, health and pharma industry necessitates the need for a routine and valid method to extract and quantify inulin present in most of the plant materials of Indian origin. Aim of this study was to extract inulin using ethanol and water as extracting solvents and compare the inulin content extracted from various plant sources using two spectrophotometric methods. The result indicated that inulin extracted using both the solvents when determined spectrophotometrically showed chicory, dahlia and onion as good sources while banana, taro and barley with low inulin. Thin layer chromatogram of inulin extracts showed the presence of fructose, glucose, sucrose and inulin and also other saccharides. The analysis of inulin content can be made efficient with suitable preparation or extraction method combined with an appropriate bioanalytical method to screen different sources. For routine study, either ethanol or water can be used to extract inulin along with a rapid and sensitive spectrophotometric method like Roe’s Resorcinol method can be implemented.

SPECTROPHOTOMETRIC QUANTIFICATION OF GLICLAZIDE IN PHARMACEUTICAL DOSAGE FORM

Objective: A simple and sensitive spectrophotometric method has been proposed for quantification of Gliclazide in pure and dosage form.
 Methods: A visible spectrophotometric methods based on the ion-pair formation of drug with the dye Cresol Red (Method A) and Bromophenol Blue (Method B) in methanol medium.
 Results: A purple colour complex was formed in Method A while orange colour was obtained by Method B with maximum absorption at 510 nm and 445 nm, respectively. The Beers law was found linear over the concentration range from 30 to 200µg/ml (Method A) and from 70 to 230µg/ml (Method B) with good correlation coefficients 0.9918 and 0.9916 respectively. The molar extinction coefficient were 0.1326 x 104 L/mol/cm (Method A) and 0.1294 x 104L/mol/cm (Method B), LOD 0.2563, 0.4681 and LOQ 0.6394µg/ml and 0.9256 µg/ml.
 Conclusion: The proposed methods were statistically evaluated for accuracy, precision and linearity in terms of standard deviation, percentage recovery, percentage error and relative standard deviation. The proposed methods can be applied in routine analytical and quality control laboratories for the quantification of Gliclazide. The methods are simple, sensitive, rapid and economical for the estimation of Gliclazide in pure and dosage forms.

VALIDATED SPECTROPHOTOMETRIC METHODS BASED ON CHARGE TRANSFER COMPLEXATION REACTION FOR THE DETERMINATION OF VALACYCLOVIR HYDROCHLORIDE AS ANTIVIRAL DRUG IN PHARMACEUTICAL FORMULATIONS

Objective: The present study aims to develop and validate two simple, sensitive, accurate, precise and economical spectrophotometric methods for the determination of valacyclovir HCl (VAL) in pure form and pharmaceutical formulations. Methods: The developed methods are based on the formation of charge-transfer complex between VAL as n-electron donor and quinalizarin (Quinz) or alizarin red S (ARS) as π-acceptor in methanol to form highly colored chromogens, which showed an absorption maximum at 565 and 540 nm using Quinz and ARS, respectively. The optimization of the reaction conditions such as the type of solvent, reagent concentration and reaction time were investigated. Results: Under the optimum conditions, Beer’s law is obeyed in the concentration ranges 0.5–16 and 1.0–20 μg/ml using Quinz and ARS, respectively, with good correlation coefficient (r2 ≥ 0.9994) and with a relative standard deviation (RSD% ≤ 0.70). The limits of detection and quantification were found to be 0.15 and 0.30 µg/ml for Quinz and 0.50 and 1.0 µg/ml for ARS. Conclusion: The methods were successfully applied to the determination of VAL in its pharmaceutical formulations and the validity assesses by applying the standard addition technique. Results obtained by the proposed methods for the pure VAL and commercial tablets agreed well with those obtained by the reported method.

Indirect Spectrophotometric Determination of Mebendazole Using Methyl Orange Dyein the Presence of the Oxidizing Agent NBS

Aim: To develop a swift , simple, accurate and sensitive spectrophotometric method for determination of mebendazole (MBZL) in pure and pharmaceutical formulations. Methods: The suggested method depend on oxidation of MBZL with known excess amount of N-bromosuccinimide ( NBS ) in acidic medium and after reaction is insured to be complete , the surplus NBS is estimated by de colorization of methyl orange (MO) dye and measuring the absorbance of surplus dye at 508 nm. A linear calibration curve was obtained over the concentration range 2.5– 25 μg.ml-1 with correlation coefficient of 0.9997. The molar absorptivity and sandell's sensitivity index values were determined to be 1.505 × 104 L.mol-1.cm-1 and 0.019607 μg.cm-2. The limit of detection (LOD) and quantification (LOQ) were calculated to be 0.3736 and 2.553 μg.ml-1, respectively. The proposed method has been successfully applied to the determination of MBZL in available dosage form, the validity proposed method was confirmed by recovery study via standard addition technique . Keywords: mebendazole ; N-bromosuccinimide ; Determination ;Spectrophotometry ; methyl orange

Diazotized reagent for spectrophotometric determination of glyphosate pesticide in environmental and agricultural samples

A new sensitive spectrophotometric method for the determination of glyphosate herbicide in environmental and agricultural samples is developed. The reaction is based on diazotization followed by coupling of glyphosate with p-dimethyl amino benzaldehyde. The resulted complex absorption spectra was observed at λmax = 420 nm. The effects of other metal ions and pesticides were also tested for selective determination of glyphosate. The analytical parameters were optimized and have been successfully applied for determination of glyphosate in various environmental samples such as soil, water and vegetables. This method has a lower limit detection of 6 μg of glyphosate. Beer's law is obeyed over the concentration range of 6.0 μg–24.0 μg glyphosate in 25 mL of the final solution at 420 nm. The standard deviation and relative standard deviation calculated are 0.0055 and 1.023, respectively. The molar absorptivity of the colored system is 1.91 × 1010 L mol−1cm−1 and Sandell's sensitivity is found 0.408 × 10−5 μg cm−2. The proposed method is simple, sensitive, highly reproducible and time saving as compare to those complicated time consuming methods.