The aim of the work was to develop and validate a spectrophotometric method for determining metoprolol tartrate in tablets based on the reaction with bromocresol green (BCG).
Material and methods. ...Analytical equipment: two-beam UV-visible spectrophotometer Shimadzu model -UV 1800 (Japan), software UV-Probe 2.62, laboratory electronic balance RAD WAG AS 200/C, pH-meter И-160МИ. The following APIs, dosage forms, reagents and solvents were used in the work: pharmacopoeial standard sample (CRS) of metoprolol tartrate (Sigma-Aldrich, (≥ 98 %, HPLC)), BCG (Sigma-Aldrich, (≥ 98 %, HPLC)), "Metoprolol" tablets 50 mg (Kyivmedpreparat, series 0035415), "Metoprolol" 100 mg (Farmak, series 30421), methanol (Honeywell, (≥ 99.9 %, GC)), ethanol (Honeywell, (≥ 99.9 %, GC)), chloroform (Honeywell, (≥ 99.9 %, GC)), acetonitrile (Honeywell, (≥ 99.9 %, GC)), and ethyl acetate (Honeywell, (≥ 99.7 %, GC)).
Results and discussion. A spectrophotometric method was developed for determining metoprolol tartrate by reaction with BCG in a methanol solution using the absorption maximum at a wavelength of 624 nm. Stoichiometric ratios of reactive components were established, which were 1:1. The developed method for the quantitative determination of metoprolol tartrate was validated following the requirements of the SPhU. The analytical method was linear in the concentration range of 5.47-38.30 μg/mL. The limit of detection and quantification were 0.41 μg/mL and 1.24 μg/mL, respectively. According to the «greenness» pictogram of the analytical method using the AGREE method, the score was 0.79, which indicates that the proposed spectrophotometric method for the determination of metoprolol was developed in compliance with the principles of «green» chemistry.Conclusions. A spectrophotometric method for determining metoprolol tartrate in tablets based on the reaction with BCG in compliance with the principles of «green» chemistry has been developed and validated. Furthermore, the developed method for the quantitative determination of metoprolol tartrate was validated following the requirements of the SPhU. In summary, the developed method has a low negative impact on the environment and can be applied for routine pharmaceutical analysis
Метою роботи була розробка і валідація спектрофотометричної методики визначення метопрололу тартрату в таблетках на основі реакції з бромкрезоловим зеленим (БКЗ) з дотриманням принципів «зеленої» хімії.
Матеріали та методи. Аналітичне обладнання: двопроменевий УФ-видимий спектрофотометр Shimadzu модель –UV 1800 (Японія), програмне забезпечення UV-Probe 2.62, ваги лабораторні електронні RAD WAG AS 200/C, pH–метр И-160МИ. У роботі використовували наступні АФІ, лікарські форми, реагенти і розчинники: фармакопейний стандартний зразок (ФСЗ) метопрололу тартрату (Sigma-Aldrich, (≥ 98 %, ВЕРХ)), БКЗ (Sigma-Aldrich, (≥ 98 %, ВЕРХ)), таблетки «Метопролол» 50 мг (Київмедпрепарат, серія 0035415), «Метопролол» 100 мг (Фармак, серія 30421), метанол (Honeywell, (≥ 99.9 %, ГХ)), етанол (Honeywell, (≥ 99.9 %, ГХ)), хлороформ (Honeywell, (≥ 99.9 %, ГХ)), ацетонітрил (Honeywell, (≥ 99.9 %, ГХ)) та етилацетат (Honeywell, (≥ 99.7 %, ГХ)).
Результати та обговорення. Розроблено спектрофотометричну методику визначення метопрололу тартрату за реакцією з БКЗ у метанольному розчині з використанням максимуму поглинання за довжини хвилі 624 нм. Встановлено стехіометричні співвідношення реакційноздатних компонентів, що становили 1:1. Розроблена методика кількісного визначення метопрололу тартрату валідована відповідно до вимог ДФУ. Аналітична методика була лінійною в діапазоні концентрацій 5.47-38.30 мкг/мл. Межа виявлення та межа кількісного визначення становили 0.41 мкг/мл і 1.24 мкг/мл відповідно. Згідно піктограми «зеленості» аналітичної методики з використання методу AGREE бал становить 0.79 та вказує на те, що запропонована спектрофотометрична методика визначення метопрололу розроблена з дотримання принципів «зеленої» хімії.
Висновки. Розроблено і валідовано просту та економічно доступну спектрофотометричну методику визначення метопрололу тартрату в таблетках на основі реакції з БКЗ з дотриманням принципів «зеленої» хімії. Розроблена методика кількісного визначення метопрололу тартрату валідована відповідно до вимог ДФУ. Підсумовуючи, розроблена методика має низький негативний вплив на навколишнє середовище та може бути застосована для цілей рутинного фармацевтичного аналізу
•Effective removal of bromocresol green dye using acid functionalized corn cob.•Freundlich, Khan, and Marczewski-Jaroniec isotherm best described the isotherm study.•ANN, ANFIS, and RSM showed ...significant modeling ability for BCG dye removal.•ANFIS model was the most efficient followed by ANN and then RSM models.•Thermodynamics study indicated that the process was spontaneous and endothermic.
Genetic algorithm (GA) assisted optimization was used in the adsorptive removal of bromocresol green (BCG) from solution. The adsorbent was acid-functionalized corn cob (AFCC). The properties of the adsorbent were investigated via instrumental analysis involving Fourier Transform Infra-Red (FTIR) and Scanning electron microscopy (SEM). Non-linear modeling involving various degrees of isotherm models were used in the isotherm study. Adaptive neuro-fuzzy inference systems (ANFIS), response surface methodology (RSM), and artificial neural network (ANN) were used to model the BCG removal. The result of the instrumental analysis showed that the properties of the AFCC were enhanced after the acid carbonization process with a surface area of 903.7 m2/g. The modeling and predictive adeptness of the ANFIS, RSM, and ANN was very significant with correlation coefficient (R2) of 0.9984, 0.9865, and 0.9979 with root mean square error (RMSE) of 0.00308, 0.00898, and 0.00351, respectively. Validation of the models’ optimization indicated maximum adsorption capacities of 38.04, 34.41, and 41.94 mg/g for RSM-GA, ANN-GA, and ANFIS-GA, respectively. Freundlich, Khan, and Marczewski-Jaroniec isotherms best described the adsorption isotherm for two-term, three-term, and four-term isotherm modeling respectively. Calculated values of Gibbs free energy change (∆Gmax = -7.55 KJ/mol), enthalpy change (∆H = 35.84 KJ/mol), and entropy change (∆S = 130.20 Jmol−1K−1) indicated the adsorption process was spontaneous, endothermic and with increased randomness respectively. The study showed that the low-cost AFCC obtained from agro-waste has desirable adsorbent properties for the treatment of BCG polluted wastewater.
The objective of this study was to develop two simple and selective visible spectrophotometric methods for the determination of antihistamine drug triprolidine hydrochloride (TRH) in the capsules. ...The methods were based on the formation of ion-pair complexes between TRH and two dyes, namely, bromocresol green (BCG) and bromophenol blue (BPB). The produced ion-pair complexes were measured at 415 and 410 nm for BCG and BPB methods, respectively. Beer’s law was applicable in the concentration ranges of 2.50-15.0 µg mL-1 TRH for both methods. The molar absorptivity values were found to be 2.12 × 104 and 2.07 × 104 L mol-1 cm-1 for the BCG method and BPB method, respectively, and the Sandell’s sensitivity values were 0.0149 and 0.0152 µg cm-2. The limits of detection and quantification were calculated and found to be 0.29 and 0.86 µg mL-1 for the BCG method and 0.31 and 0.95 µg mL-1 for the BPB method. The methods were applied successfully for TRH determination in bulk drug and in the capsules.
Photocatalytic activity of CuS incorporated into an Iranian clinoptilolite (CuS-Cp) was studied for decolorization of a mixture of Methyl Orange and Bromocresol Green under sunlight irradiation. All ...samples were characterized by XRD, FTIR, DRS and TG/DTG techniques. The effect of some key experimental parameters such as: amount of the catalyst (0.05–5gL−1), initial concentration of dyes (5–30mgL−1), solution pH (1–11) and also dosage of H2O2 and KBrO3 was studied on the decolorization extent. The extent of decolorization was estimated from the residual concentration by spectrophotometrically and it was confirmed by the reduction of chemical oxygen demand (COD).
pH is a “master variable” controlling many biogeochemical processes in soils. Acid sulfate soils undergo rapid and large pH changes from circumneutral pH under anaerobic soil conditions to sulfuric ...soils with ultra (pH < 3.5) and extremely (pH 3.5–4.4) acidic properties following oxidation. Measuring soil pH using a glass electrode has several potential drawbacks including liquid junction errors, drift, suspension effects and clogging. Spectrophotometric pH measurement, involving addition of an indicator dye to the sample, is widely used in seawater and has recently been developed for soil extracts at circumneutral pH ranges. The aim of this study was to extend the spectrophotometric method for application in ultra and extremely acidic soils. The acid dissociation constant (pKa = 5.02) and molar absorptivities of the indicator dye bromocresol green were determined and shown to enable spectrophotometric pH measurement between pH 3 − 5.3. To demonstrate the performance and application of the method, pH and metal availability (Fe, Al, Zn) were measured during the incubation of two acid sulfate soils, which both classified as hypersulfidic soils (pH > 4) and transformed to sulfuric soils (pH < 4) after incubation for 12 weeks. The method compared well (r2 > 0.99) to glass electrode measurements under acidic conditions with high metal availability. The method has potential to improve understanding of biogeochemical processes in ultra and extremely acidic soils.
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•A spectrophotometric method was developed for pH measurement in acidic soils.•Bromocresol green dye properties were characterised at low ionic strength.•An acid sulfate soil incubation was used to validate the method between pH 3 − 5.3.•Results compared well to glass electrode pH measurements in the acidic range.•High metal availability in acidic soils did not significantly affect dye function.
•An integrated 3-D μPAD platform is proposed for whole blood albumin (ALB) detection.•BCG reagent and ALB concentration is induced albumin-BCG complex for RGB detection.•ALB concentration of 30 ...real-world human whole blood samples are measured.
A method is proposed for determining the concentration of albumin (ALB) in human whole blood samples using a 3-dimensional (3D) microfluidic paper-based chip and a smart detection module. In fabricating the paper-based chip, the reaction area is implanted with bromocresol green (BCG) reagent and the device is stored in a nitrogen (N2) environment at a temperature of —15 °C until needed for use. In the detection process, 10 μl of whole blood is dropped onto the entrance area of the chip and the plasma within the sample diffuses through a separation channel into the reaction zone. A reaction is induced between the ALB in the plasma and the BCG reagent in the reaction area by heating the chip at 37 °C for 6 min. The ALB concentration is then detected using a colorimetry technique implemented on a cell phone in the form of a self-written app. It is shown that the detection results obtained for 40 pure ALB samples and 30 whole blood samples are consistent with those obtained using a traditional spectrophotometry method (R2 = 0.9837 and R2 = 0.9968). The proposed detection system thus provides a reliable tool for practical ALB determination purposes.
The methods for determination of chitosan content recommended in the Chinese Pharmacopoeia and the European Pharmacopoeia are not applicable for evaluation of the extent of deacetylation ...(deacetylation degree, DD) in chitooligosaccharides (COS). This study explores two different methods for assessment of DD in COS having relatively high and low molecular weights: an acid-base titration with bromocresol green indicator and a first order derivative UV spectrophotometric method for assessment of DD in COS. The accuracy of both methods as a function of molecular weight was also investigated and compared to results obtained using ¹H NMR spectroscopy. Our study demonstrates two simple, fast, widely adaptable, highly precise, accurate, and inexpensive methods for the effective determination of DD in COS, which have the potential for widespread commercial applications in developing country.
Degradation of bromocresol green in alcohol-water solution using ozone micron sized bubbles is reported. A high speed impeller is used to generate micro bubbles of ozone in liquid while ozone is ...generated using a commercial ozone generator. A 3-level-3-factor Box–Behnken experimental design is used to statistically identify relative importance of the operating parameters studied namely impeller speed, initial concentration of dye and treatment time. Ozone dosage is kept fixed at 4 g/h. Impeller speed is found to be the most dominant factor according to Analysis of Variance (ANOVA) calculations. Kinetics for degradation of bromocresol green in solution is also reported. A second order kinetics is seen to fit the experimental (concentration–time) data, corresponding value of rate constant being 0.0153 L/mg-s. Based on the laboratory scale data a detailed techno-commercial analysis of a scaled up (75 kL/day) plant for ozone based degradation of bromocresol is presented. All relevant economic indicators pertaining to the scaled up plant are reported. A specific treatment cost of Rs. 100/m
3
of treated water yields a return on investment (ROI) of 68.77 and discounted payback period of 5 years.
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