Evaluation of turbidimetric and nephelometric techniques for analytical determination of n-acetylcysteine and thiamine in pharmaceutical formulations employing a lab-made portable microcontrolled turbidimeter and nephelometer

Santos, Vagner Bezerra dos; Guerreiro, Thiago Brito; Suarez, Willian Toito; Faria, Ronaldo C.; Fatibello‐Filho, Orlando

doi:10.1590/s0103-50532011001000019

Cited by 14 publications

(8 citation statements)

References 29 publications

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“…Recording of experimental data, and visualization of the time of switching on the valves on the LCD screen are others functions developed by the microcontroller. All the functions of the device are previously developed in C programming language [4,5,[7][8][9].…”

Section: Microcontrolled Pumping Flow System (µC-pfs)mentioning

confidence: 99%

“…Firstly, the carrier solution (supporting electrolyte) is pumping from the proper reservoirs (E) by the aquarium air pump (P) with fixed (5); confluence connection (6); electrochemical flow cell (7); control buttons (8) and LCD screen (9).…”

Section: Manifold and Operation Procedures Of The µC-pfsmentioning

confidence: 99%

“…This device is able to perform commands and instructions, which are driven by a code that can be loaded and storage into the memory of the microcontroller. In analytical chemistry, microcontrollers have been used for the construction of photometers, [4] spectrophotometers, [5] fluorimeters, [6] turbidimeters, [7,8] nephelometers, [8,9] potentiostats and luminometers [10]. In order to reach a full and more versatility automation, the microcontrolled instrumentation can be coupled to flow analyses procedures.…”

Section: Introductionmentioning

confidence: 99%

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A Portable Microcontrolled Pumping Flow System Developed to In Loco Determination of Diuron at Nanomolar Levels Employing a Disposable Biosensor

Janegitz¹,

Fern²,

Vicentini³

et al. 2015

J Anal Bioanal Tech

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Microcontrolled systems coupled biosensors have attracted attention. Here, we describe an automated and portable microcontrolled pumping flow system (µC-PFS) developed to biosensing application. The flow system is fully automatic, portable, it works in battery module and it dispenses the use of microcomputer and the manual operations. This device presents mainly a microcontroller as central processing unit (CPU), an aquarium air pump and three-way solenoid valves to propulsion and the volume control of aliquots inserted in the flow system. Once available its performance, this device was used to pump samples and solution towards a compacted and miniaturized electrochemical flow cell (EFC) employing a multicommutated flow procedure. In the EFC, it was used a biosensor based on acetylcholinesterase immobilized on the gold nanoparticles modified-screen printed carbon electrode, which was used in order to perform the determination of diuron by enzymatic inhibition employing a chronoamperometry. Under the best experimental conditions, the calibration curve for diuron determination was linear in the concentration range from 80 to 1400 nmol/L with a detection limit of 50 nmol/L. Moreover, the proposed system was fully automated, showed precise, with low consumption of sample and waste generation with an analytical throughput of 13/h.

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Section: Microcontrolled Pumping Flow System (µC-pfs)mentioning

confidence: 99%

Section: Manifold and Operation Procedures Of The µC-pfsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A Portable Microcontrolled Pumping Flow System Developed to In Loco Determination of Diuron at Nanomolar Levels Employing a Disposable Biosensor

Janegitz¹,

Fern²,

Vicentini³

et al. 2015

J Anal Bioanal Tech

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“…It is extensively used as a component of single vitamin B complex and multivitamin preparations [2][3][4]. Several analytical methods, including UV and visible spectrophotometric and multivariate analysis [5][6][7], fluorimetric [8][9][10][11][12][13][14][15][16][17][18][19][20][21], high performance liquid chromatography (HPLC) [22][23][24][25][26][27][28][29][30][31][32][33][34][35], UHPLC/MS-MS [36], turbidimetric and nephelometric [37], amperometric [38], and voltammetric methods [39][40][41][42][43][44][45], have been used for the assay of thiamine and its salts in pharmaceutical preparations, food materials and biological fluids. Some of these methods have previously been reviewed [46][47][48]…”

Section: Introductionmentioning

confidence: 99%

Stability-Indicating Photochemical Method for the Assay of Thiamine by Spectrophotometry

Ahmad

Abbas

Anwar

et al. 2018

Journal of Spectroscopy

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A stability-indicating photochemical method has been developed for the assay of thiamine (TH) salts in aqueous solution and in fresh and aged vitamin preparations. It is based on the photooxidation of TH by UV irradiation to form thiochrome (TC) in alkaline solution. e TC : TH ratio under controlled conditions of light intensity, temperature, pH, exposure time, and irradiation distance is constant and can be used to determine the concentration of UV irradiated TH solutions. TC, on extraction with isobutanol from the photodegraded solution of TH, has been determined by the UV spectrophotometric method at 370 nm. It exhibits a high intensity of absorption in the UV region that can be used for the assay of even low concentrations of TH. Under optimum conditions, Beer's law is obeyed in the concentration range of 0.20-2.00 mg/100 ml (R 2 � 09998). e limit of detection (LOD) and limit of quantification (LOQ) are 0.0076 and 0.0231 mg/100 ml, respectively. e method has been validated and applied to aqueous solutions and vitamin preparations. e results have statistically been compared with the United States Pharmacopeia liquid chromatography method. It has been found that there is no significant difference between the two methods at 95% confidence level.

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“…Recent studies have revealed that NAC inhibits muscle fatigue and can be used to enhance performance in exercise and endurance training. [1][2][3] Analytical techniques like colorimetry, 4,5 chemiluminiscence, 6,7 electrochemical detection, [8][9][10][11][12][13][14][15] flurimetry, 16,17 turbidimetry and nephlometry, 18 liquid chromatography tandem mass spectrometry, 19-21-44 gas chromatography mass spectrometry, 22,23 and capillary electrophoresis [24][25][26] have been employed in literature for the quantification of acetyl cysteine. Acetyl cysteine has also been simultaneously quantified along with other drugs like clomiphene citrate, 27 arginine, 28 and cefexime trihydrate.…”

Section: Introductionmentioning

confidence: 99%

Development and Validation of an Analytical Method for Related Substances in N-acetyl–L-cysteine Effervescent Tablets by RP-HPLC

Mathew¹,

Ravi²,

Rameshwar³

et al. 2017

IJPER

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Background:The reported chromatographic methods for N-acetyl cysteine [NAC] are reverse phase HPLC and ion pair chromatography [IPC] for related substances test in bulk and in formulations. No reported stability indicating methods for the estimation of related substances in NAC effervescent formulation was found in literature. Objective: The present work was aimed at developing a selective, sensitive and reproducible stability indicating high-performance liquid chromatographic method for the quantitative determination of known, unknown impurities, degradation impurities and processrelated impurities of NAC effervescent formulation. Method: A reversed phase ion pair chromatographic method was developed employing Cadenza C18 column as the stationary phase and 0.01M octane sulphonate [pH 2.20], methanol and acetonitrile in the ratio 90:8:2 as the mobile phase. A gradient programme was followed with a run time of 55 minutes. 0.3 M hydrochloric acid was selected as the optimum diluent. The performance of the method was validated according to the ICHQ2R1 guidelines. Results: The method was found to be linear from 1.5 to 25µg/ml for impurities A, C and D and from 2.0 to 25 µg/ml for impurity B. The official impurities C and D were mapped in all stress conditions. Additionally, impurity B was also seen in acidic conditions. Conclusion: The results from the study demonstrate that the method is suitable for evaluating the stability of NAC effervescent tablet. Key words: N-acetyl cysteine, Reverse phase HPLC, Effervescent formulation, Ion pair chromatography, Related substances,Validation. Key message: An ion pair chromatographic method was developed for quantifying the related substances of N-acetyl cysteine effervescent Tablets. Selection of diluent was an important variable in the method development.

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Evaluation of turbidimetric and nephelometric techniques for analytical determination of n-acetylcysteine and thiamine in pharmaceutical formulations employing a lab-made portable microcontrolled turbidimeter and nephelometer

Cited by 14 publications

References 29 publications

A Portable Microcontrolled Pumping Flow System Developed to In Loco Determination of Diuron at Nanomolar Levels Employing a Disposable Biosensor

A Portable Microcontrolled Pumping Flow System Developed to In Loco Determination of Diuron at Nanomolar Levels Employing a Disposable Biosensor

Stability-Indicating Photochemical Method for the Assay of Thiamine by Spectrophotometry

Development and Validation of an Analytical Method for Related Substances in N-acetyl–L-cysteine Effervescent Tablets by RP-HPLC

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