Acid In Pure Form Research Articles

Novel procedures for olive leaves extracts processing: Selective isolation of oleuropein and elenolic acid

Several processes have been developed in the past to selectively extract oleuropein and its aglycones from olive derived materials. In the present manuscript, we outline a novel approach for processing olive leaves aqueous extracts. This allowed first to select microwave irradiation as the methodology able to provide a large enrichment in oleuropein. Subsequently, the use of lamellar solids led to the selective and high yield concentration of the same. Adsorption on solids also largely contributed to the long term chemical stability of oleuropein. Finally, an eco-friendly, readily available, and reusable catalyst like H2SO4 supported on silica was applied for the hydrolysis of oleuropein into hydroxytyrosol and elenolic acid. This latter was in turn selectively isolated by an acid-base work-up providing its monoaldehydic dihydropyran form (7.8 % extractive yield), that was unequivocally characterized by GC–MS. The isolation of elenolic acid in pure form is described herein for the first time.

Standardization and Evaluation of Triphala Juice and Quantification of Gallic Acid as a Biomarker by Analytical Techniques

Background:: Standardization of Triphala Juice was performed by using the WHO Guidelines. The Parameters included Preliminary Analysis, Phytochemical Identification, Heavy Metal Estimation, etc. A new simple, specific, precise and accurate UV Spectrophotometric, High-Performance Liquid Methods: Chromatography and High-Performance Thin Layer Chromatography method has been developed for the Estimation of Gallic Acid in pure form. The UV- Spectrophotometric method was developed using Schimadzu 1800 UV - Visible spec-trophotometer using methanol as a solvent. The method was shown to be linear, with a detection wavelength of 273 nm for Gallic Acid. The separation was achieved on the Schimadzu Prominence-I RP-HPLC and the column used was C18 column using mobile phase consisting of mixture of Methanol: 0.1% OPA (50:50). The detection was carried out at 280 nm with a flow rate of 0.7ml/min. The retention time for Gallic Acid was found 3.89 minutes. The calibration curve was found linear (r2 = 0.999) for RP- HPLC method. The HPTLC method was developed using Aetron Sprayline instrument, Methanol as solvent and mobile phase consisting of Toluene: Ethyl Acetate: Formic Acid: Methanol (3:3:0.9:0.2). The method was found linear and the wavelength of detection for Gallic Acid was 254nm, respectively. The percentage recoveries for both methods were found in the 98.0- 102.0% range. Results:: The methods were validated in accordance with International Conference on harmoniza-tion acceptance criteria for specificity, linearity, precision, accuracy, robustness and system suita-bility. The excipients did not interfere in the determination of Gallic acid in Triphala Juice. Conclusion:: The suggested approach was effectively implemented for the quantitative determina-tion of gallic acid in Triphala juice, which would aid in quality control

Indirect Spectrophotometric Determination of Mefenamic Acid using Safranin Dye

A simple, accurate, and rapid indirect spectrophotometric method has been developed for the determination of mefenamic acid in its pure form and in pharmaceutical preparations. The method is based on the oxidation of the mefenamic acid by N-bromosuccinimide (NBS) (excess) and estimating the amount of unconsumed NBS by safranin dye in the presence of the acid and the surfactant SDS in the aqueous medium at λmax = 527 nm. Regression analysis of Beer–Lambert's plot proves excellent correlation in the concentration ranges 0.025 – 5 μg mL-1 with a correlation coefficient 0.993. A molar absorptivity, Sandell sensitivity, and limits of detection (LOD) and quantification (LOQ) were calculated to be 2.05×104 L mol-1 cm-1, 0.0117 μg cm-2, 0.254 μg mL-1 and 0.847 μg mL-1, respectively. The possibility of quantitative determination of mefenamic acid in pure form and in pharmaceutical preparations in the form of syrup and capsules with average recoveries 102.57 %, 100.88 %, and 100.57 %, and RSD ≤ 1.69 %, ≤1.42 % and ≤1.89 % also, respectively, are shown.

High cell density cultivation of Corynebacterium glutamicum on bio-based lignocellulosic acetate using pH-coupled online feeding control

Acetate represents a promising alternative carbon source for future industrial biotechnology. In this study, the high potential of Corynebacterium glutamicum for utilizing acetate as sole carbon source was demonstrated. Batch culture studies revealed that C. glutamicum ATCC 13032 naturally exhibits high acetate tolerance with maximum growth rates (µmax = 0.47 h−1) similar to those on D-glucose. Based on a simple and auto-regulated pH-coupled feeding strategy which utilizes bio-acetic acid in pure form, a novel and high-efficient fed-batch process was developed in a 42 L stirred-tank bioreactor. By optimizing the carbon-to-nitrogen (C/N) feeding ratio, maximum biomass concentrations of 80.2 gCDW/L were achieved with a space–time yield of 66.6 gCDW/L·d. In addition, a process model was implemented describing the time-courses of biomass growth and substrate concentrations. This is the first study in which an industrial platform organism was grown to high cell densities using green, lignocellulosic acetate as an alternative carbon source.

An innovational validated spectrofluorimetric technique for determination of 6-Aminocaproic acid in pure form and its tablet: Application to spiked human plasma and urine

An innovative and sensitive spectrofluorimetric method has been developed for determination of 6-aminocaproic acid (ACA) in its pure form and its laboratory prepared tablets. The aim of this method is the reaction of ethyl acetoacetate and formaldehyde with the primary amino group presented in ACA as aimed in the Hantzsch reaction, this reaction resulted in formation of a yellow fluorescent dihydropyridine derivative that can be easily detected spectrofluorimetrically at 438 nm (excitation at 358 nm). At the optimum conditions of the reaction, the linear range was found to be (0.7–3.5 µg\\mL) with limit of detection is 0.231 µg\\mL and limit of quantitation is 0.700 µg\\mL. The proposed method used for detection of ACA laboratory prepared tablets with average percentage 100.721 ± 0.701% without any interference from any excipients. This method used for in vitro determination of ACA in spiked human plasma with a percent mean recovery 99.874 ± 1.416%. In addition, the developed method used for determination of ACA in spiked human urine with percent mean recovery 100.314 ± 1.793%.

Derivatization of tranexamic acid for its rapid spectrofluorimetric determination in pure form and pharmaceutical formulations: Application in human plasma.

An ingenious approach for determination of tranexamic acid spectrofluorimetrically has been developed. This experiment is very simple, sensitive and selective method for determination of tranexamic acid in pure form, pharmaceutical dosage forms and in spiked human plasma. All optimal conditions needed in our proposed experiment have been determined and validated precisely. This developed method based on the reaction between the primary amino group found in the chemical structure of tranexamic acid with the fluorescamine reagent in presence of borate buffer (pH 8.3) that result in the formation of fluorescence product measured at 473.5nm after excitation at 392nm. We notice that the linearity of the resulted calibration curve found to be (0.1-0.9μg/mL) with LOD and LOQ results were 0.0237 and 0.0719 respectively. The validation of the developed method is according to the international council for Harmonization (ICH) guidelines indicating good accuracy and precision. Finally, the developed method has been applied for in vitro study of tranexamic acid by making spiked human plasma with a mean percentage recovery 99.430±0.623 as well as in its pharmaceutical dosage forms tablets and ampoules.

Spectrofluorimetric approach for determination of tranexamic acid in pure form and pharmaceutical formulations; Application in human plasma

Tranexamic acid (TXA) is an important antihemorrhagic drug that needs a simple, sensitive and low cost spectrofluorimetric method for its determination. This method depends on generation of a yellow product which produced from a nucleophilic substitution reaction of the lone pair of electrons on the amino group found in the TXA chemical structure and 4-chloro-7-nitrobenzofurazan (NBD-Cl) in borate buffer PH 9.0. The product was measured at 536nm (λex=470.5nm). All variables that have an effect on the formation and stability of the product have been explored and optimized. The linear range was 20-100ngmL-1 with a limit of quantitation 12.4ngmL-1. This method has been applied for assurance of tranexamic acid in ampoules and tablets dosage forms without any interference from excipients present. Also, we study the drug in human plasma.

ЭФФЕКТИВНОСТЬ ПРИМЕНЕНИЯ ХИМИЧЕСКИХ И БИОЛОГИЧЕСКОГО ПРЕПАРАТОВ ДЛЯ КОНСЕРВИРОВАНИЯ ПЛЮЩЕНОГО ЗЕРНА КУКУРУЗЫ

Experimental data on the effectiveness of the use of the chemical and biological preparation for the conservation of rolled corn. The effectiveness of the use of preparation was determined by organoleptic indicators, acidity, acidification rate, organic acid content, chemical and nutritional composition of the feed, comparing them with the option of preserved without the use of preparation (control). Digestibility and energy nutrition were determined by calculation using formulas taken from the guidelines for assessing the quality and nutritional value of feed. Digital material was processed by the statistical method of small samples with establishing the reliability of the difference (P) between the options on a PC using the Microsoft Office software package. As a result of research, the effectiveness of the use of formic acid in pure form, as well as in a mixture with ammonia 85:15, with ammonia, propionic and benzoic acids in the ratio 50:20:2:10, 40:40:2:5 and AIV for the preservation of rolled corn. They allows acidifies feed for optimal acidity value necessary for long-term storage of feed and maintain it throughout the storage period, increases the content of raw and digestible protein, feed units, metabolic energy in the resulting feed.

Titrimetric application of 2-bromo-bis-1, 10-phenanthroline-copper (II) bromide as a titrant in determination of ascorbic acid in pure form, fruits and vegetables

Titrimetric application of 2-bromo-bis-1, 10-phenanthroline-copper (II) bromide as a titrant in determination of ascorbic acid in pure form, fruits and vegetables

Spectrophotometric determination of Mefenamic acid viadiazo coupling reaction using different reagents in dosage forms

Three simple, accurate and precise spectrophotometric methods were proposed for determining of mefenamic acid in pure form as well as in dosage forms. The proposed methods were based on the coupling of mefenamic acid with diazotized 4-aminohippuric acid, 4-nitroaniline and 4-aminoantipyrine in alkaline medium for methods A, B and C, respectively. The colored azo dyes were quantitated photometrically at 432, 453, and 406 nm for methods A, B and C, respectively. Different variables affecting the reactions were optimized. Beer’s law was obeyed over the concentration ranges of 0.5-20, 1.0-16 and 0.2-14 μg/ml for methods A, B, and C, respectively. The colored azo dyes remained stable for more than 3 hours in the three methods. The proposed methods were applied successfully to determine mefenamic acid in dosage forms.

Indirect spectrophotometric determination of folic acid based on the oxidation reaction and studying some of the thermodynamic parameters

A simple and sensitive indirect spectrophotometric method was developed for the determination of folic acid in pure form and in its pharmaceutical formulations. The method was based on the oxidation of folic acid by iron (III) in acidic medium, then reaction of liberated iron (II) with 2, 2'-bipyridyl to produce a red complex which is water-soluble, stable, and has a maximum absorption at 520 nm against the reagent blank with a molar absorptivity of 2.8338 x 105 L .mol-1.cm-1. Beer’s law is valid over the concentration range of 0.5-18.0 µg/ml folic acid. The values of some thermodynamic parameters [free energy change (∆G), enthalpy change (∆H), and entropy change (∆S)] were estimated from the values of stability constants (K) at different temperatures .It was found that colored product formation was spontaneous, exothermic and accompanied by an increase of random. The proposed method has been applied successfully to determine folic acid in different pharmaceutical preparations.

High Performance Liquid Chromatographic Method for Determination of Ascorbic Acid in Pure Form, Pharmaceutical Formulations, Biological Samples and in Environmental Water Samples

A simple, precise, rapid, and accurate reversed–phase high performance liquidchromatographic method has been developed for the determination of ascorbic acid in purefrom, pharmaceutical formulations, biological samples and in environmental water samples.Chromatography was carried out on supercar L1 (C18 ) reversed- phase column (25cm×4.6mm), 5 microns, using a mixture of methanol : water (42: 58v/v) as a mobile phase at aflow rate of 1.0 ml.min-1.Detection was performed at 254nm at ambient temperature.The retention time for ascorbic acid was found 2.3 minutes. The calibration curve waslinear (r= 0.9998) over a concentration range from 0.5 to 12.5μg/ml. Limit of detection(LOD) and limit of quantitation (LOQ) were found 3ng/ml and 9 ng/ml respectively. Themethod was validated for its linearity, precision and accuracy.The proposed method was successfully applied for the determination of ascorbic acidin pure form, pharmaceutical formulations, and biological samples and in environmentalwater samples.

Transdermal absorption enhancement of gel containing elastic niosomes loaded with gallic acid from Terminalia chebula galls

Objectives: To investigate transdermal absorption enhancement of gel containing elastic niosomes loaded with gallic acid in the semipurified fraction isolated from Terminalia chebula Retz. (Combretaceae) galls.Materials and methods: Nonelastic and elastic niosomes loaded with gallic acid in pure form or in the semipurified fraction were developed. Rat skin permeation by vertical Franz diffusion cells of gallic acid from various gel formulations containing elastic niosomes loaded with gallic acid or the semipurified fraction was performed.Results: Elastic and nonelastic niosomes loaded with gallic acid or the semipurified fraction exhibited the mixture of unilamellar and multilamellar structures with negative zeta potential values and in the size range of 200–400 nm. Both loaded elastic and nonelastic niosomes showed good physical and chemical stability for 3 months. The percentages remaining of gallic acid in nonelastic were slightly higher than in elastic niosomes. Both elastic and nonelastic niosomes retarded rat skin permeation of the loaded pure gallic acid, while enhanced the loaded gallic acid in the semipurified fraction. However, elastic niosomes exhibited higher percentages of gallic acid through rat skin than the nonelastic niosomes.Discussion and conclusion: This study has demonstrated the potential of niosomes, especially elastic niosomes, for the enhancement of chemical stability and rat skin transdermal absorption of gallic acid in the semipurified fraction from T. chebula galls, which will be beneficial for topical antiaging application.

Spectrophotometric determination of [2-(2,6-dichloro-phenylamino)-phenyl]-acetic acid in pure form and in pharmaceuticals

A new sensitive and selective spectrophotometric method has been developed for the determination of [2-(2,6-dichloro-phenylamino)-phenyl]-acetic acid in pharmaceuticals in the presence of nicotinic acid. The method is based on the reaction of [2-(2,6-dichloro-phenylamino)-phenyl]-acetic acid with 1,3,3-trimethyl-5-phenyl-2-[3-(1,3,3-trimethyl-1,3-dihydro-indol-2-ylidene)-propenyl]-3 H-indolium chloride (PIC) followed by the extraction of the formed ion associate into toluene and spectrophotometric detection at 581 nm. Appropriate experimental conditions were found to be pH 7.8–9.8 and 3.6 × 10 −4 mol L −1 of PIC. The molar absorptivity is 5.0 × 10 −4 L mol −1 cm −1. The absorbance obeys Beer's law in the range 0.61–12.60 μg mL −1 of [2-(2,6-dichloro-phenylamino)-phenyl]-acetic acid, and the detection limit calculated from a blank test was 0.20 μg mL −1.

Spectrophotometric Determination of Mefenamic Acid in Pharmaceutical Preparations Via Arsenazo III – Cerium (III) Reaction*

A sensitive indirect spectrophotometric method is proposed for determining mefenamic acid in pure form and in its pharmaceutical preparations. The method is based on oxidation-reduction reaction between mefenamic acid and cerium (IV) ion, and subsequent Ce(III) reaction with arsenazo (III) reagent in acidic medium to produce a greenish-blue complex which is stable, water soluble and has a maximum absorption at 654 nm with a molar absorptivity of 1.731105 l.mol-1.cm-1. Beer’s law is obeyed in the concentration range from 1 to 10 g mefenamic acid in a final volume of 25 ml. The proposed method has been applied successfully to determine mefenamic acid in pharmaceutical preparations.

Spectrophotometric techniques to determine tranexamic acid: Kinetic studies using ninhydrin and direct measuring using ferric chloride

Two simple and sensitive spectrophotometric methods in ultraviolet and visible region are described for the determination of tranexamic acid in pure form and pharmaceutical preparations. The first method is based on the reaction of the drug with ninhydrin at boiling temperature and by measuring the increase in absorbance at 575 nm as a function of time. The initial rate, rate constant and fixed time (120 min) procedures were used for constructing the calibration graphs to determine the concentration of the drug, which showed a linear response over the concentration range 16–37 μg mL −1 with correlation coefficient “ r” 0.9997, 0.996, 0.9999, LOQ 6.968, 7.138, 2.462 μgmL −1 and LOD 2.090, 2.141 and 0.739 μgmL −1, respectively. In second method tranexamic acid was reacted with ferric chloride solution, yellowish orange colored chromogen showed λ max at 375 nm showing linearity in the concentration range of 50–800 μg mL −1 with correlation coefficient “ r” 0.9997, LOQ 6.227 μgmL −1 and LOD 1.868 μgmL −1. The variables affecting the development of the color were optimized and the developed methods were validated statistically and through recovery studies. These results were also verified by IR and NMR spectroscopy. The proposed methods have been successfully applied to the determination of tranexamic acid in commercial pharmaceutical formulation.

Colorimetric Determination of Two Nonsteroidal Anti-inflammatory Drugs Using P-Dimethylaminocinnamaldehyde

A colorimetric method for the quantitative determination of diclofenac sodium and mefenamic acid in pure form and in pharmaceutical preparations was developed. It was based on the inter-action of the secondary aromatic amine with p-dimethyl-aminocinnamaldhyde in acidified absolute methanol medium to form very stable red [λmax at 538 nm in case of diclofenac sodium] or blue [λmax at 665 nm in case of mefenamic acid] products. Beer's law was obeyed over the ranges 10–80 μg ml−1 and 1–8 μg ml−1 for diclofenac sodium and mefenamic acid, respectively. The reactants were heated on a boiling water bath for 6 and 5 mins for each drug, respectively. Optimization of the different experimental conditions were studied. The mean percentage recoveries were found to be 100.73 ± 0.87% & 100.73 ± 0.44%, respectively. The method was applied successfully for the determination of some pharmaceutical formulations. The validity of the suggested procedure was assessed by applying the standard addition technique.

Determination of ascorbic acid by flow injection with chemiluminescence detection

Flow injection was used in combination with chemiluminescence detection to determine 30 amol of ascorbic acid based on a luminol–Fe3+–hydrogen peroxide system. The method was applied to the determination of ascorbic acid in pure form, pharmaceutical preparations and fruit juices. The method is sensitive, rapid (sampling rate 2–56 samples h–1) and tolerates the presence of common ingredients usually found in fruit juices and drug formulations.

Spectrophotometric determination of ascorbic acid in pharmaceutical preparations and fruit juices.

Conditions were established for the determination of ascorbic acid using phsophovanadotungstic acid as reagent. The method was applied to the determination of ascorbic acid in pure form, pharmaceutical preparations and fruit juices. The method is sensitive (2-24 micrograms ml-1 of ascorbic acid) and rapid and tolerates the presence of common ingredients usually found in fruit juices. The results obtained with the proposed method showed good agreement with those given by the standard method.

ISOLATION AND DETERMINATION OF STRUCTURE OF A NEW AMINO ACID CONTAINED WITHIN THE TOXIN OF PSEUDOMONAS TABACI

When the phytopathogenic toxin of Pseudomonas tabaci, the causative agent of wildfire disease of tobacco, is hydrolyzed with strong HCl, a ninhydrin-positive substance is produced (1). Because this substance moved on paper chromatograms more slowly than the recognized a-amino acids’ and because of its ready destruction by chloramine-T, the tentative conclusion was reached that hydrolysis of this toxin liberated a previously unknown amino acid. The object of this paper is t,o describe the isolation of this new amino acid in pure form and to tell of the determination of its structure as a, E-diamino-fl-hydroxypimelic acid. Because this amino acid is contained within the toxin of P. tabaci, the short, trivial name tabtoxinine is proposed for it. The structure was established in the following manner. Elementary analyses showed that the isolated substance corresponded to the formula C,H1406N2. Aqueous solutions of it were neutral. Measurement of carbon dioxide evolved showed that practically all the nitrogen was estimable by the decarboxylation procedure with ninhydrin, and this behavior strongly indicated that the nitrogen atoms were present as amino groups situated (Y to carboxyl groups. These facts suggested that the new compound was a hydroxydiaminopimelic acid, and this seemed to correlate well with its migration on paper strips. Work (2) has recently described the isolation of a!, E-diaminopimelic acid from hydrolysates of the diphtheria bacillus, and has shown that it migrates slowly on paper strips developed with phenol.’ The finding t,hat our new compound (which differed in empirical formula from that of Work by only 1 oxygen atom) moved even more slowly (RF 0.10 in phenol saturated with water) was enough t’o suggest that it might be a hydroxydiaminopimelic acid. This proved to be the case. The position of the hydroxyl group was established as being adjacent to one of the amino groups by the use of sodium periodate. This reagent rapidly destroyed the new amino acid and 1 equivalent of periodate was consumed in the process. After this reaction a small amount of a sub-