Spectrophotometric Method For Assay Research Articles

Development of validated analytical area under curve UV spectrophotometric method for assay of cetrizine dihydrochloride

Development of validated analytical area under curve UV spectrophotometric method for assay of cetrizine dihydrochloride

Assessment of Plasma Sodium to Potassium Ratio, Renal Function, Markers of Oxidative Stress, Inflammation, and Endothelial Dysfunction in Nigerian Hypertensive Patients.

Background This study investigated plasma sodium/potassium ratio, markers of oxidative stress, renal function, and endothelial dysfunction in hypertensive Nigerians. Materials and Methods Five hundred forty-nine volunteers consisting of three hundred and twenty-four hypertensive and two hundred twenty-five controls participated in this study. Blood samples were collected from the participants and were analyzed for electrolytes, markers of oxidative stress, endothelial dysfunction, renal function, and inflammation, using ion-selective electrodes, spectrophotometric, and enzyme-linked immunosorbent assay methods, respectively. Results The mean systolic blood pressure, mean diastolic blood pressure, mean arterial blood pressure, and body mass index (BMI) were significantly elevated among the hypertensive group when compared with control (p < 0.001). The mean sodium increased, while potassium and bicarbonate (HCO3−) decreased (p < 0.001) in hypertensive volunteers. The sodium-potassium ratio (Na+/K+) and urea were raised (p < 0.001) in the hypertensive group when compared with the control. Glutathione, superoxide dismutase, nitric oxide (NO), and catalase were significantly reduced (p < 0.001) while malondialdehyde (MDA), high-sensitivity C-reactive protein (hs-CRP), and ferritin were raised significantly (p < 0.001) in hypertensive participants. The odds of hypertension and its complications increased (p < 0.001) with an increase in BMI, Na+/K+, hs-CRP, MDA, and ferritin and a decrease in estimated glomerular filtration rate (eGFR), glutathione, superoxide dismutase, and catalase. Conclusion An increase in Na+/K+, urea, hs-CRP, ferritin, MDA, and BMI and a decrease in eGFR, glutathione, and superoxide dismutase were associated with an increased risk of hypertension complication. Abnormal values of markers of oxidative stress, inflammation, and endothelial function could impact deleterious effects on the cardiovascular system among hypertensive Nigerians. A decreased bicarbonate possibly suggests an occult acid-base imbalance among hypertensive volunteers.

The protective role of melatonin against the effects of different doses of caffeine on the fetus

Skeletal system and some organs development changes in rat fetuses with 30 and 60 mg/kg caffeine and melatonin's (10 mg/kg) protective role against rat fetuses were investigated. Groups (n = 4) were formed as Control, LDC, HDC, LDC+melatonin, HDC+melatonin and melatonin. Fetuses were taken by cesarean section and stained using dual skeletal staining method and FESEM. TRAP and AP immune-reactivity concentrations were calculated. Oxidative stress and inflammatory markers were also measured by liver, bone and placenta samples. TNF-α, IL-1ß, IL-6, VEGF-A, SOST and Fetuin-A levels were measured in tissue by using ELISA. TBARS, SOD, GSH, GSSG, TOS, TAS, measured by spectrophotometric assay method. The mRNA levels of Agtr2 gene expressed in placental tissues of control rats and in placental tissues of rats exposed to HDC, LDC, MEL, HDC+MEL, LDC+MEL were analyzed by Real-time PCR. The gene expressions of Agtr2 were significantly upregulated in the placentas exposed to HDC, MEL, HDC+MEL and LDC+MEL (P&lt;0,001). No significant difference in samples of the LDC group (P&gt;0,05). According to these data, caffeine used during pregnancy delayed ossification; melatonin, a powerful antioxidant, was found to eliminate this effect. Besides, changes in angiotensin receptor expression observed in response to a caffeine and melatonin exposure result from high dose and join effect.

Automated Assessment of Hematoma Volume of Rodents Subjected to Experimental Intracerebral Hemorrhagic Stroke by Bayes Segmentation Approach

Simulating a clinical condition of intracerebral hemorrhage (ICH) in animals is key to research on the development and testing of diagnostic or treatment strategies for this high-mortality disease. In order to study the mechanism, pathology, and treatment for hemorrhagic stroke, various animal models have been developed. Measurement of hematoma volume is an important assessment parameter to evaluate post-ICH outcomes. However, due to tissue preservation conditions and variables in digitization, quantification of hematoma volume is usually labor intensive and sometimes even subjective. The objective of this study is to develop an automated method that can accurately and efficiently obtain unbiased cerebral hematoma volume. We developed an application (MATLAB program) that can delineate the brain slice from the background and use the Hue information in the Hue/Saturation/Value (HSV) color space to segment the hematoma region. The segmentation threshold of Hue is calculated based on the Bayes classifier theorem so that the minimum error is mathematically ensured and automated processing is enabled. To validate the developed method, we compared the outcomes from the developed method with the hemoglobin content by the spectrophotometric assay method. The results were linearly correlated with statistical significance. The method was also validated by digital phantoms with an error less than 5% compared with the ground truth from the phantoms. Hematoma volumes yielded by the automated processing and those obtained by the operator's manual operation are highly correlated. This automated segmentation approach can be potentially used to quantify hemorrhagic outcomes in rodent stroke models in an unbiased and efficient way.

Indirect Spectrophotometric Determination of Diclofenac and Isoxsuprine Drugs Using N-bromosuccinimide and Malachite Green Dye

Simple, accurate and sensitive indirect spectrophotometric method for assay of diclofenac (Di) and Isoxsuprine (IS) in pure and pharmaceutical formulation has been developed. The method is based on oxidation of (Di) and (IS) by N-bromosuccinimide in acidic medium. The excess of oxidant is determine by reaction with malachite green dye and the absorbance is measured at 615nm. Under the optimized experimental conditions, Beer's law is obeyed in concentration range 0.5-18 , 1-18 µg/ml with molar absorptivity 5.1×104 and 4.6×104 L.mol-1.cm-1 for (Di) and (IS) respectively. The limits of detection (LOD) 0.0314, 0.038 and quantification are 0.0104 , 0.126 µg/ml. with the accuracy (average recovery) 100.80%, 101.20% for above drugs respectively and the precision (RSD) less than 1.5% for both drugs. The proposed method is applied successfully for assay of pharmaceutical formulations.

Spectrophotometric method for designation of nitrobenzene by using o-chloranil so application in Diyala River and waterproof case

A reproducible, critical and simple spectrophotometric method for assay of RNB was investigated is based on (charge transfer complex) formation reaction of RNB with O-Chloranil reagent in the presence of sodium bicarbonate in ethanol to give a highly coloured species with maximal absorption at 440 nm, As well Beer’s law was obeyed in the range of (5-50) µg.mL with a molar absorptivity of 1.21×104 L.mol−1.cm−1 and the limit of detection and quantitation were 0.059 and 0.242 µg.mL respectively. The (average recovery rate) was 101.65% and relative standard deviation (RSD) was better than 0.55%. In addition, it was ratio of 1:1. The method was successfully applied to assay of RNB in Diyala river water and waterproof case.

Development of Validated UV Spectrophotometric Method for Assay of Ozagrel and its Pharmaceutical Formulations

UV Spectrophotometric method was developed and validated for the quantitative determination of Ozagrel in bulk drug and in pharmaceutical formulations. Ozagrel shows the maximum absorbance at 270 nm. Ozagrel follows Beer’s law in the concentration range of 1.0-10.0 µg/ml (r = 0.999). The detection limit (DL) and quantitation limit (QL) were 0.4629 and 1.4027 µg/ml respectively. Accuracy and precision were found to be satisfactory. The developed methods were validated according to ICH guidelines. All the validation parameters were found to be satisfactory accordance with the standard values. Therefore, the proposed method can be used for routine practice for the determination of Ozagrel in assay of bulk drug and pharmaceutical formulations.

Antioxidant Activities of Cinnamaldehyde Derivatives

The modification structures of cinnamaldehyde, which was isolated from cinnamon oil, has been carried out. The synthesized compounds were tested their antioxidant activity by using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging assay and the IC50 was done by spectrophotometric assay method compared with standard vitamin E. The cinnamaldehyde derivatives, e.g. cinnamic acid 2, methyl cinnamate 3 and cinnamyl alcohol 5 had significantly higher antioxidant activity than that of their starting materials, cinnamaldehyde. However, although cinnamic amine 5 had a hydroxyl group, it gave no antioxidant activity possibly due to its bulky structure.

СПЕКТРОФОТОМЕТРИЧНЕ ВИЗНАЧЕННЯ АТЕНОЛОЛУ У ЛІКАРСЬКИХ ФОРМАХ З ВИКОРИСТАННЯМ 2,3-ДИХЛОР-1,4-НАФТОХІНОНУ

Мета роботи. Розробка та валідація методики кількісного визначення атенололу в лікарських формах із використанням методу абсорбційної спектрофотометрії.Матеріали і методи. В дослідженні використано робочий стандартний зразок атенололу, 2,3-дихлор-1,4-нафтохінон, зразки готових лікарських форм вітчизняного виробництва.Результати й обговорення. Експериментально встановлено, що 2,3-дихлор-1,4-нафтохінон взаємодіє з атенололом у середовищі ДМФА з утворенням забарвленої сполуки з максимумом абсорбції при 493 нм. Проведена валідація розробленої методики. Визначені основні валідаційні характеристики, а саме лінійність, прецизійність, правильність, робасність та діапазон застосування. Підпорядкування закону Бера спостерігається в межах концентрацій 11,20–19,60 мг/100 мл, коефіцієнт кореляції становить 0,9990. Параметри лінійної залежності розраховані за допомогою регресійного аналізу методом найменших квадратів. Запропонована методика відповідає вимогам ДФУ, які висувають до методик кількісного аналізу лікарських речовин.Висновки. Розроблено та валідовано спектрофотометричну методику кількісного визначення атенололу, яка успішно застосована для аналізу лікарських форм. Результати дослідження свідчать, що методика є точною, простою у виконанні та придатною для використання в лабораторіях контролю якості лікарських речовин.

Pinaverium Bromide: Development and Validation of Spectrophotometric Methods for Assay and Dissolution Studies.

This study presents the development and validation of UV spectrophotometric methods for the determination of pinaverium bromide (PB) in tablet assay and dissolution studies. The methods were satisfactorily validated according to International Conference on Harmonization guidelines. The response was linear (r2 > 0.99) in the concentration ranges of 2-14 μg/mL at 213 nm and 10-70 μg/mL at 243 nm. The LOD and LOQ were 0.39 and 1.31 μg/mL, respectively, at 213 nm. For the 243 nm method, the LOD and LOQ were 2.93 and 9.77 μg/mL, respectively. Precision was evaluated by RSD, and the obtained results were lower than 2%. Adequate accuracy was also obtained. The methods proved to be robust using a full factorial design evaluation. For PB dissolution studies, the best conditions were achieved using a United States Pharmacopeia Dissolution Apparatus 2 (paddle) at 50 rpm and with 900 mL 0.1 M hydrochloric acid as the dissolution medium, presenting satisfactory results during the validation tests. In addition, the kinetic parameters of drug release were investigated using model-dependent methods, and the dissolution profiles were best described by the first-order model. Therefore, the proposed methods were successfully applied for the assay and dissolution analysis of PB in commercial tablets.

Validation of analytical method for determination of furosemide in extemporaneous syrup

Introduction. Extreme syrups can be manufactured using substances or ready medicinal drugs as the active pharmaceutical ingredient. There is a necessity in the development and validation of analytical methods that can be used for quality control of pharmaceutical manufacturing of syrups containing furosemide.The aim of the study – to develop and validate assay method for furosemide in extemporaneous syrups prepared from both pure substance and finished products. Methods of the research. For proposed UV spectrophotometric assay method the conditions of analysis, sample preparation and validation characteristics were defined. Suspensions of substance and crushed commercial tablets were dissolved in 0.1 M sodium hydroxide solution and evaluated spectrophotometrically in ultraviolet region of light at a wavelength 271 nm using method of specific absorbance.Results and Discussion. Samples comply with the Beer-Lambert Bouguer law within the concentration range of 8×10-3 – 1.2×10-2 mg/ml with correlation coefficients ≥ 0.9981. The uncertainty of the methods was well within the critical value of the error (0.72 %≤ maxΔAs) for both samples of syrup containing pure substance and commercial tablets. Recovery studies for furosemide in syrup samples of substance and crushed commercial tablets yielded 99.92 ±0.54 % and 99.14±0.16 % respectively. Assay limit of ±10 % by the validation parameters: specificity, linearity, precision, accuracy within the range of 80–120 % of the nominal contents was met by all compounded preparations.Conclusions. The results of validation proved that this method can be reproduced correctly and is suitable for use in pharmaceutical analysis. Adoption of this method is planned in evaluating uniformity of content and, in combination of other methods, ascertain chemical stability study of compounded furosemide syrups.

РОЗРОБКА ТА ВАЛІДАЦІЯ СПЕКТРОФОТОМЕТРИЧНОЇ МЕТОДИКИ КІЛЬКІСНОГО ВИЗНАЧЕННЯ ЕНІСАМІУМУ ЙОДИДУ В КАПСУЛАХ

Мета роботи. Розробити методику кількісного визначення енісаміуму йодиду в капсулах із застосуванням методу абсорбційної спектрофотометрії в ультрафіолетовій області.Матеріали і методи. Використано стандартний зразок енісаміум йодиду та зразок готової лікарської форми виробництва ПАТ «Фармак». У ході роботи було встановлено оптимальну робочу концентрацію енісаміуму йодиду 0,02 мг/мл. Дослідження проводили із застосуванням спектрофотометра «Specord 250 Plus».Результати й обговорення. Продемонстровано, що оптимальна довжина хвилі при визначенні становить 267 нм. Вивчено валідаційні характеристики методики в діапазоні 0,016-0,024 мг/мл (80-120%): специфічність, правильність, прецизійність, лінійність, діапазон застосування, робасність, внутрішньолабораторна прецизійність відповідно до рекомендацій Міжнародної конференції з гармонізації. Коефіцієнт кореляції (r) між введеним та знайденим значенням для енісаміуму йодиду становить 0,99996, а відносний довірчий інтервал (Dz) 0,23 %. Підтверджено стабільність розчинів при їх зберіганні при кімнатній температурі протягом 48 годин.Висновки. Розроблено спектрофотометричну методику кількісного визначення енісаміуму йодиду в капсулах, експериментально доведено, що вона придатна для контролю якості капсул енісаміуму йодиду.

Spectrophotometric method for the quantitative assay of N-hydroxysulfosuccinimide esters including extinction coefficients and reaction kinetics

A quantitative spectrophotometric method has been developed for the analysis of N-hydroxysulfosuccinimide (sulfo-NHS), a chromophore with a maximum absorbance at 268 nm. The extinction coefficients were determined between pH 6.0 and 8.0 and found to vary in a nonlinear manner. This spectrophotometric profile is not present in its esters which however release an equimolar amount of sulfo-NHS when they react with nucleophilic groups or hydrolyze in aqueous solution. This fact facilitates the determination in solution of the concentration and purity of bis(sulfosuccinimidyl) suberate (BS3) used as a model, as well as the examination of hydrolysis and aminolysis half-lives in different reaction conditions, these parameters being valuable in optimization of the use of the active esters.

Spectrophotometric Methods for Simultaneous Determination of Rivaroxaban and Clopidogrel in Their Binary Mixture

Three rapid, accurate and very simple derivative spectrophotometric methods for RIV and CLP assay in their binary mixture and tablet dosage forms were developed. Method (I) is first derivative spectrophotometric method, derivative amplitudes were measured at the zero crossing wavelength of 289 and 249.5 nm for estimation of RIV and CLP, respectively. The linearity is over the range 2.0 - 20.0 μg/ml for RIV and 5.0 - 60.0 μg/ml for CLP with LOD of 0.211 and 0.361 μg mL-1 and LOQ of 0.641 and 1.095 μg mL-1 for RIV and CLP, respectively. Method (II) is ratio derivative spectrophotometric method. The ratio spectra of each drug were derived by dividing its spectra on a constant concentration of the other drug as a divisor. Derivative amplitudes were measured at 256 nm for RIV and at 214.5 nm for CLP over the same linearity range as the first method with LOD of 0.137 and 0.485 μg mL-1 and LOQ of 0.417 and 1.471 μg mL-1 for RIV and CLP, respectively. Method (III) is absorbance ratio method, absorbance of both drugs were recorded at two wavelengths λ1 (232) iso-absorptive point and λ2 (249) λmax of RIV. The final concentrations were obtained by applying the Q equations. The method was linear over the same concentration range as the first method with LOD of 0.272 and 0.485 μg mL-1 and LOQ of 0.826 and 1.471 μg mL-1 for RIV and CLP, respectively. The proposed methods were validated as per ICH guidelines. The proposed methods were successfully applied to both drugs analysis in their laboratory prepared co formulated tablet. Statistical comparison of the obtained results with those of the reference method show good agreement and confirm that there were no significant difference in the accuracy and precision between the proposed and reference one respectively.

Ecto-Cyclic AMP Independent Protein Kinase-A Potent Regulator of L-type Calcium Channel and Forward Motility of Goat (Capra indicus) Epididymal Spermatozoa

Objective: Caprine (Capra indicus) spermatozoa possess a novel ecto-cAMP independent protein kinase (ecto- CIK) on their membrane surface. This enzyme showed remarkable alteration through the maturation process of spermatozoa in epididymis. We investigated the role of CIK in the regulation of forward motility of epididymal spermatozoa by controlling the intracellular level of [Ca2+].Method: Cauda epididymal mature sperm cells were treated with CIK antibody and maximum inhibition of enzyme activity (85%) was observed at 120 minutes of exposure. To analyze the calcium uptake mechanisms cells were exposed to 45Ca2+ after treatment with CIK antibody and pretreated with different calcium channel regulators. The intracellular [Ca2+]i signal was determined fluorometrically by using fura 2-AM. The computerized spectrophotometric assay method was used to measure the percentage of forward motility.Result: It was shown that the uptake of calcium through the L-type voltage-dependent Ca2+ channels of the plasma membrane is regulated by CIK. Pretreatment of sperm cells with varapamil (20 μM), nifedipine (20 μM) significantly inhibited the increased intracellular [Ca2+]i induced by the CIK antibody. Whereas calmodulin antagonists trifluoperazine and w13 (N-(4-Aminobutyl)-5-chloro-2 naphthalenesulfonamide hydrochloride and sodium azide, a potent mitochondrial inhibitor, showed no effect on this calcium entry. The treatment with ca ionophore A123187 of the CIK antibody treated cells showed channel inhibitor insensitive increase of calcium uptake. It was observed that verapamil (20 μM) has significant role in decreasing (~50%) forward motility of CIK-antibody treated spermatozoa.Conclusion: We concluded that CIK is an important regulator of forward motility in epididymal spermatozoa and the regulation may be activated partly by the intracellular [Ca2+]i level the extent of which is functionally imparted by the voltage gated L type calcium channel.

Phytochemical Content and Pharma-Nutrition Study on Eleutherococcus senticosus Fruits Intractum.

In the past two decades public interest in herbal products has increased significantly in Europe, especially in the plant-based products from non-European traditions. Eleutherococcus senticosus has been used for the treatment of inflammatory diseases, anemia, and rheumatoid arthritis. The Eleutherococcus senticosus fruits intractum was examined for the content of phenolic acids (LC-ESI-MS/MS), minerals (AAS), TPC, and TFC (spectrophotometric assay). The antioxidant activity was determined using free radical scavenging assay and TLC-DB-DPPH∗ dot-blot test. An anti-Hyal activity was evaluated by the spectrophotometric assay method. Cytotoxicity towards HL-60, HL-60/MX1, HL-60/MX2, CEM/C1, and CCRF/CEM leukemic cell lines was done using trypan blue test. Among eight phenolic acids, trans-caffeic acid was found in the largest amount (41.2 mg/g DE). The intractum presented a high amount of macroelements (Ca, Mg, K; 1750, 1300, and 21000 mg/kg) and microelements (Fe, Mn; 32.7, 54.3 mg/kg), respectively. The content of TPC and TFC was 130 and 92 mg/g DE, respectively. The intractum showed anti-Hyal activity (2.16–60%) and an antioxidant capacity (EC50; 52 μg/mL). The intractum most strongly inhibited the growth of HL-60, HL-60/MX1, and CCRF/CEM. A better understanding of the intractum health benefits is important in order to increase its utility and enrich dietary sources of health promoting compounds.

Rapid and direct spectrophotometric method for kinetics studies and routine assay of peroxidase based on aniline diazo substrates

Peroxidases are ubiquitous enzymes that play an important role in living organisms. Current spectrophotometrically based peroxidase assay methods are based on the production of chromophoric substances at the end of the enzymatic reaction. The ambiguity regarding the formation and identity of the final chromophoric product and its possible reactions with other molecules have raised concerns about the accuracy of these methods. This can be of serious concern in inhibition studies. A novel spectrophotometric assay for peroxidase, based on direct measurement of a soluble aniline diazo substrate, is introduced. In addition to the routine assays, this method can be used in comprehensive kinetics studies. 4-[(4-Sulfophenyl)azo]aniline (λmax = 390 nm, ɛ = 32 880 M−1 cm−1 at pH 4.5 to 9) was introduced for routine assay of peroxidase. This compound is commercially available and is indexed as a food dye. Using this method, a detection limit of 0.05 nmol mL−1 was achieved for peroxidase.

English

Polyvinyl alcohol (PVA) degrading bacterial strains were isolated from various environmental sites rich in plastic wastes by using the enrichment culture technique. Among the various isolated strains, the selected potent PVA degrading bacterial strains were tentatively characterized as Bacillus and Pseudomonas sp. The time course of the PVA degradation potential of the characterized strains in growth media containing PVA as a major carbon source was evaluated using the spectropho-tometric assay method. This was done by determining the residual PVA remaining in the culture media, increase in cell growth and change in pH of the media over a period of twenty days. The ultimate biodegradation (mineralization) of PVA to its mineral constituents CO2 and H2O was determined by the CO2 evolution test. The strain characterized as Bacillus sp. showed 65% of PVA degradation as determined by spectrophotometric assay and 45.4% of mineralization of PVA over a period of 20 days. The strain characterized as Pseudomonas sp. showed 42% of PVA degradation as determined by spectrophoto-metric assay and 28.9% of mineralization of PVA over a period of 20 days. Key words: Polyvinyl alcohol (PVA) degrading bacteria, isolation, ultimate biodegradation, mineralization.

Comparison of Spectrophotometric and Titrimetric Methods for Assay of 2-Phenethyldithiocarbamoylacetic Acid, a Novel Anticancer Drug

Spectrophotometric and titrimetric methods for assay of 2-phenethyldithiocarbamoylacetic acid (PET) substance were compared in terms of accuracy and reproducibility using experimental and statistical methods. Random errors in the mean results of the spectrophotometric and titrimetric methods were no greater than 0.26% (n = 8, p = 0.95) and 0.11% (n = 7, p = 0.95) respectively. Systematic errors in both methods were smaller than random errors. Both methods gave reproducible and accurate results and can be recommended for assay of PET in substance.

The Antioxidant Activity from Hydroquinone Derivatives by the Synthesis of Cinnamomium Verum J.Presl Bark’s Extracted

Hydroquinone is polyphenol compound which was used as antioxidant. In this study, the hydroquinone was synthesized via aldol condensation between 1,4-cyclohexanedione and cinnamaldehyde which was extracted from the bark of Cinnamomum verum J.Presl by stream distillation and using LiCl as a catalyst in pyridine. The hydroquinone derivatives showed the dark brown crystal with Rf 0.50 (hexane : ethyl acetate : methanol 5 : 4 : 1). These products were characterized by FT-IR spectroscopy which showed spectrum at 3300 - 3500 cm -1 (O-H stretching), 3025 cm-1 (C-H stretching of aromatic), 1660 cm -1 (C=C stretching of alkene) and 1450, 1502 cm -1 (C=C stretching of aromatic), respectively. The characterization by 1 H-NMR spectroscopy expressed 1 H-NMR (ppm): 9.70 (d, 2H, OH), 6.35-7.56 (m, 8H, aromatic protons) and 3.50 (d, 2H, -CH2-), respectively. The synthesized product was tested the antioxidant activity by using DPPH radical scavenging assay and the IC50 was done by spectrophotometric assay method compared with standard gallic acid. The antioxidant activity revealed that IC50 were 14.15 ppm.