scholarly journals Application of Hantzsch reaction for sensitive determination of eflornithine in cream, plasma and urine samples

2021 ◽  
Vol 8 (5) ◽  
Author(s):  
Albandary Almahri ◽  
Mohamed A. Abdel-Lateef
Keyword(s):  
Heating Temperature ◽  
Heating Time ◽  
Current Approach ◽  
Facial Hair ◽  
Selective Determination ◽  
Ich Guidelines ◽  
Dihydropyridine Derivative ◽  
Plasma And Urine Samples ◽  
Time Buffer

Eflornithine (EFN) is an anti- Trypanosoma brucei agent for the medication of sleeping sickness and widely distributed for the treatment of hirsutism (unwanted facial hair in women). The presented work demonstrates a comprehensive analytical approach for the spectrofluorometric determination of EFN in commercial cream samples and various biological samples. The proposed method is based on the formation of a highly yellow–green fluorescence dihydropyridine derivative after the interaction between EFN and acetylacetone/formaldehyde reagent in a slightly acidic medium. Furthermore, the optimal variables such as reagent volumes, pH of the medium, heating time, buffer volume, heating temperature and diluting solvent were carefully selected to achieve the maximum fluorescence activity. The fluorescence activity for the formed derivative was measured at λ emission = 477 nm after λ excitation = 418 nm. Concerning linearity, accuracy, sensitivity, precision and robustness, the presented method was validated and verified according to ICH guidelines. Moreover, the proposed work offered a selective determination for EFN in various brands of pharmaceutical cream without any interference from excipients. Eventually, the current approach was assured to be successful in the estimation of EFN in urine and plasma samples with acceptable recovery results.

scholarly journals SPECTROPHOTOMETRIC DETERMINATION OF PYROCATHECOL AND PYROGALLOL BASED ON THEIR REDOX REACTION WITH IRON(III)/PHENANTHROLINE SYSTEM

2010 ◽  
Vol 2 (3) ◽  
pp. 161-166 ◽  
Author(s):  
Mudasir Mudasir ◽  
Mugiyanti Mugiyanti ◽  
Ngatidjo Hadipranoto
Keyword(s):  
Phenolic Compounds ◽  
Redox Reaction ◽  
Heating Temperature ◽  
Heating Time ◽  
Maximum Absorption ◽  
Optimum Conditions ◽  
Phenanthroline Complex ◽  
Maximum Absorption Wavelength ◽  
Absorption Wavelength

An analytical method for the spectrophotometric determination of some phenolic compounds, i.e.: pyrocathecol and pyrogallol based on their redox reaction with iron(III)-phenanthroline complex has been developed. These two compounds, in appropriate conditions, reduce iron(III)-phenanthroline complex to yield very stable and color-intense complex of iron(II)-phenanthroline, [Fe(phen)2]2+, whose concentration is equivalent to the amount of pyrocathecol or pyrogallol in the solution, and is easily detected by spectrophotometric method. Some parameters influencing the sensitivity of the determination were optimized. These included maximum absorption wavelength, pH of the solution, time and temperature of heatingand reagent to analyte minimum mole-ratio. Using the optimum conditions obtained, the analytical performance of the method was examined and the developed method was then applied to analyzed pyrocathecol and pyrogallol contents in several river water of Yogyakarta, Indonesia. Result of the study showed that the optimum conditions for the determination of pyrocathecol are as follows: maximum absorption wavelength (lmax) at 510 nm, pH of the solution = 4, heating time = 120 min, heating temperature = 70 0C and the minimum mole ratio of reagent to analyte is 8. On the other hand, the optimum conditions for the determination of pyrogallol are as follows: maximum absorption wavelength (lmax) at 510 nm, pH of the solution = 5, heating time = 90 min, heating temperature = 90 0C and the minimum mole ratio of reagent to analyte is 7. At the corresponding conditions of analysis, calibration curves for pyrocathecol and pyrogallol are linear in the range concentration of 0.00 - 0.16 ppm and 0.00 - 0.24 ppm, respectively. The correlation coefficients for both compounds were found to be higher than 0.998 and the detection limits went down below 0.07 ppm. It has been demonstrated that the developed method can be applied for the determination of pyrocathecol and pyrogallol contents in natural samples.   Keywords: Spectrophotometry, phenolic compounds, 1,10-phenanthroline, redox reaction

Based on the Protection of Water Pack Polysaccharide Processing Technology and its Optimization

2014 ◽  
Vol 1056 ◽  
pp. 107-113
Author(s):  
Yun Long Zhu ◽  
Qian Qian Wang ◽  
Yang Yuan ◽  
Jing Jing Zhu
Keyword(s):  
Heating Temperature ◽  
Retention Rate ◽  
Heating Time ◽  
Processing Method ◽  
Slice Thickness ◽  
Optimal Process ◽  
Frying Time ◽  
Heating Treatment ◽  
Baked Products

Purpose: For health water pack polysaccharide easy loss occurred during processing, establish a high retention rate of the processing method. Method: Chooseing slice thickness, heating time and temperature as the parameter, the water pack for steaming, boiled, Fried, baked oil heating treatment, determination of the water pack polysaccharide content, it is concluded that optimal process parameters, the retention rate of statistics. Results: The best conditions for water pack all kinds of processing method is: (1) steamed products: slice thickness of 1.6 cm, 106 °C steamed 10 mins; (2) boiled products: slice thickness of 1.2 cm, 90 °C cooked for 10 mins; (3) baked products: the slice thickness of 0.2 cm, 160 °C baking 14 mins; (4) Fried products: the slice thickness of 0.2 cm, and 150 °C the frying time of 5.5 mins. Processing products in water pack polysaccharide retention rate is as follows: Steaming > Boiled > Fried > Baking. Conclusion: steamed processing for water pack polysaccharide retention rate is high, is the water pack of preferred processing method; Boiled, grilled, Fried method should choose low heating temperature.

scholarly journals EFFECT OF VARIOUS FACTORS ON THE FORMATION OF AMINOREDUCTONE DURING THE MAILLARD REACTION

2018 ◽  
Vol 51 (6) ◽  
pp. 703
Author(s):  
Vu Thu Trang
Keyword(s):  
Maillard Reaction ◽  
Phosphate Buffer ◽  
Heating Temperature ◽  
Heating Time ◽  
Model Solution ◽  
Amino Compound ◽  
Buffer Concentration ◽  
Maillard Reactions ◽  
Initial Stage ◽  
Time Buffer

To create a basis for the production of aminoreductone (AR) followed by the use of it as a functional ingredient in food supplements, the effects of heating temperature, heating time, buffer concentration and reducing sugar/amino compound ratio on the formation of aminoreductone (AR), a product formed during the initial stage of the Maillard reaction,were investigated. In the model solution of lactose (262 mM) and butylamine (1.16 M) in 1.28 M phosphate buffer (pH 7.0), AR formation increased during the prolongation of the heating time at heating temperature less than 100oC. In the heated model solution at 100 oC, the maximum amount of AR was obtained as soon after 10 min of heating time. After that, the decreases of the AR formation was observed by the progress of the advanced reactions of AR. The rates of AR formation increased with the increasing phosphate buffer concentration. Moreover, the increasing in AR formation incorporated in the increase of the butylamine/lactose ratio from 0.1 to 5. Our results might give more insight in the discovery of Maillard reactions in food because it suggested tendency of the AR formation and to control the formation of AR during food processing and model system base on the control of initial constituents and reaction conditions. 

scholarly journals Optimization and validation of a new chromatographic method for the assay of veterinary formulation

2019 ◽  
Vol 10 (3) ◽  
pp. 218-223
Author(s):  
Hany Hunter Monir ◽  
Adel Magdy Michael ◽  
Christine Kamal Nessim ◽  
Yasmin Mohamed Fayez ◽  
Nahla Salah Elshater
Keyword(s):  
Reversed Phase ◽  
Hplc Method ◽  
Uv Detection ◽  
Fixed Dose ◽  
Selective Determination ◽  
Ich Guidelines ◽  
Significant Difference ◽  
Dose Combination ◽  
Student’S T

New, validated and accurate reversed phase HPLC method with UV detection has been established for simultaneous determination of a veterinary binary mixture of doxycycline hydrochloride (DOX) and tylosin tartrate (TYT). The stationary phase was ACE- 126-2546 AQ C-18 (250 × 4.6 mm i.d., 5 μm particle size) column at 25 °C, in an isocratic mode, using mobile phase containing a mixture of methanol: acetonitrile: distilled water in the ratio of 60:20:20 (v:v:v), with 0.01% trichloroacetic acid at the flow rate of 0.8 mL/min and UV detection was performed at 270 nm. The retention times were 4.02±0.01 and 5.62±0.01 mins for DOX and TYT, respectively. Selective determination of the cited veterinary drugs has been developed in their formulation. The method was found to be linear over 1-50 µg/mL for DOX and TYT with mean percentage recoveries 99.62±1.220 and 100.09±1.104%. The method was proven to be accurate, precise and specific. The obtained results were statistically compared with those of the official and reported methods; using Student’s t test, F test and one-way ANOVA, showing no significant difference with high accuracy. Specificity of the applied method was assessed by analysing the laboratory-prepared mixtures and their combined dosage form. The developed method was confirmed according to ICH guidelines. The validated method can be considered as alternative and basic method for the routine determination of this fixed dose combination with minimum sample preparation.

UV spectroscopic method for determination of phenytoin in bulk and injection forms

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Quality Control ◽  
Spectrophotometric Method ◽  
Spectroscopic Method ◽  
Ich Guidelines ◽  
Precision And Accuracy ◽  
Routine Quality Control

Recent study was conducted to develop a simple UV spectrophotometric method to determine Phenytoin in bulk and injection form according to official requirement and validate as per ICH guidelines. λmax of Phenytoin was found 202 nm. Linearity existed perceived in the concentration assortment 2-8 μg/ml (r2 = 0.999) for the method. The method was validated pertaining to linearity, precision and accuracy studies, LOD and LOQ consistent with ICH guidelines. The existent method was establish to be simple, linear, precise, accurate as well as sensitive and can be applied for routine quality control enquiry for the analysis of Phenytoin in bulk and injection form.

A Versatile Stability-indicating Liquid Chromatographic Method for the Simultaneous Determination of Atenolol, Hydrochlorothiazide and Chlorthalidone

2020 ◽  
Vol 16 (8) ◽  
pp. 1037-1051
Author(s):  
Ehab Farouk Elkady ◽  
Marwa Ahmed Fouad ◽  
Abdulgabar A. Ezzy Faquih
Keyword(s):  
Quality Control ◽  
Chromatographic Method ◽  
Degradation Products ◽  
Pharmaceutical Dosage Forms ◽  
Potassium Dihydrogen ◽  
Ich Guidelines ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Potassium Dihydrogen Orthophosphate

Background: Atenolol is a selective beta 1 blocker that can be used alone or in combination with hydrochlorothiazide or with chlorthalidone for the treatment of hypertension and prevention from a heart attack. Objective: The main target of this work was to improve modern, easy, accurate and selective liquid chromatographic method (RP-HPLC) for the determination of these drugs in the presence of their degradation products. These methods can be used as analytical gadgets in quality control laboratories for a routine examination. Methods: In this method, the separation was accomplished through an Inertsil® ODS-3V C18 column (250 mm x 4.6 mm, 5 μm), the mobile phase used was 25 mM aqueous potassium dihydrogen orthophosphate solution adjusted to pH 6.8 by using 0.1M sodium hydroxide and acetonitrile (77 : 23, v/v), the flow rate used was 1 ml/min and detection was achieved at 235 nm using UV. Results: All peaks were sharp and well separated, the retention times were atenolol degradation (ATN Deg.) 2.311 min, atenolol (ATN) 2.580 min, hydrochlorothiazide degradation (HCT Deg.) 5.890 min, hydrochlorothiazide (HCT) 7.016 min, chlorthalidone degradation CTD Deg 8.018 min and chlorthalidone (CTD) 14.972 min. Linearity was obtained and the range of concentrations was 20- 160 μg/ml for atenolol, 10-80 μg/ml for hydrochlorothiazide and 10-80 μg/ml for chlorthalidone. According to ICH guidelines, method validation was accomplished, these methods include linearity, accuracy, selectivity, precision and robustness. Conclusion: The optimized method demonstrated to be specific, robust and accurate for the quality control of the cited drugs in pharmaceutical dosage forms.

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