scholarly journals SECOND-ORDER DERIVATIVE UV SPECTROPHOTOMETRIC AND RP-HPLC METHODS FOR THE ANALYSIS OF VILDAGLIPTIN AND APPLICATION FOR DISSOLUTION STUDY

2018 ◽  
Vol 2 (1) ◽  
pp. 46-53
Author(s):  
Amanda Thomas Barden ◽  
Bruna L Piccoli ◽  
Nadia Maria Volpato ◽  
Martin Steppe
Keyword(s):  
Phosphate Buffer Solution ◽  
Potassium Phosphate ◽  
Second Order ◽  
Order Derivative ◽  
Buffer Solution ◽  
Solution Ph ◽  
Zero Crossing ◽  
Dipeptidyl Peptidase 4 ◽  
Therapeutic Class ◽  
Potassium Phosphate Buffer Solution

This study describes two analytical methods, by second-order derivative UV spectrophotometric by HPLC, for determination of vildagliptin, a drug used for treatment of type 2 Diabetes Mellitus that belongs to a therapeutic class called inhibitors of dipeptidyl peptidase 4. The methods were validated in accordance with ICH and USP requirements. Analyses by UV derivative method were performed at 220 nm, which was the zero crossing point of excipient solutions. HPLC was optimized and the analysis was carried out using a Zorbax Eclipse Plus RP-C8 column (150 mm × 4.6 mm, 5 μm), detection at 207 nm, and potassium phosphate buffer solution pH 7.0 : acetonitrile (85:15, v/v) as mobile phase. In dissolution test, the conditions used were 0.01 mol L-1 hydrochloric acid in 900 mL of dissolution medium, USP apparatus 2 (paddle) and 50 rpm stirring speed. Both methods were successfully applied for analysis of dissolution samples from marketed vildagliptin tablets.

scholarly journals Effect of combination of electrolyte and buffer on electrical production in fuel cell microbial system with Pseudomonas sp. in molasses substrate

2020 ◽  
Vol 211 ◽  
pp. 03001
Author(s):  
Maswati Baharuddin ◽  
Muh Rajib ◽  
Sappewali ◽  
Ummi Zahra
Keyword(s):  
Electrolyte Solution ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Potassium Phosphate ◽  
Salt Bridge ◽  
High Energy ◽  
Pseudomonas Sp ◽  
Buffer Solution ◽  
Sodium Phosphate Buffer ◽  
Potassium Phosphate Buffer Solution

MFC is a bio-electrochemical system driving an electric current by using high-energy bacteria and oxidants. This research aimed to investigate the effect of electrolyte and buffer on electrical production using Pseudomonas sp. In Molasses substrate. The method in this research was the double compartment that consist of anode and cathode chambers. Both were related by salt bridge. This study showed that the addition of a combination of KMnO4 electrolyte solution with sodium phosphate buffer solution obtained a maximum potential difference of 0.67 V. The result also revealed that the combination of KMnO4 electrolyte solution with Potassium Phosphate Buffer solution produced a 1.44 mA maximum current with power density of 660.82 mW/m2.

Biomechanical and biochemical changes in lumbar vertebrae of rapidly growing rats

1989 ◽  
Vol 256 (1) ◽  
pp. R259-R263 ◽  
Author(s):  
G. J. Salem ◽  
R. F. Zernicke ◽  
A. C. Vailas ◽  
D. A. Martinez
Keyword(s):  
Phosphate Buffer Solution ◽  
Lumbar Vertebrae ◽  
Potassium Phosphate ◽  
Bone Adaptation ◽  
Specimen Preparation ◽  
Buffer Solution ◽  
Test Protocol ◽  
Immature Rat ◽  
Vertebral Bone ◽  
Potassium Phosphate Buffer Solution

Although growth-related biochemical, morphological, and biomechanical properties of rat cortical bone have been investigated, similar properties of immature rat vertebral bone have not been well characterized. Information about these properties is necessary, however, for comparative analyses of rat vertebral bone adaptation. Thus a method was developed to characterize growth-related differences in immature rat vertebral bone. The centra of sixth lumbar vertebrae (L6) of 44-day-old and 54-day-old male Sprague-Dawley rats were compressed to 50% of their initial height at a 50%/s strain rate while immersed in a potassium phosphate buffer solution (pH 7.4, 37 degrees C). Structural and material properties for the 54-day-old group that were significantly greater than those for the 44-day-old group included load, stress, and energy at the proportional limit; initial maximum load and stress; and load and energy at 50% strain. The structural stiffness of L6, as well as its elastic modulus, was significantly greater in the older animals. The calcium concentrations and calcium-to-collagen ratios in 54-day-old vertebrae were significantly greater than in younger animals. These results indicated that the specimen preparation and testing protocol developed for rat vertebrae produced reliable biomechanical results, even with the relatively small size of rat vertebrae bodies, and that the quantity and quality of the matrix of immature rat vertebral bone changed significantly during this period of rapid growth. Our test protocol will be useful for investigating the responses of rat vertebral bone to exercise, disease, and spaceflight.

STUDIES ON THE AMOEBA-TO-FLAGELLATE TRANSFORMATION OF TETRAMITUS ROSTRATUS

1965 ◽  
Vol 11 (3) ◽  
pp. 441-446 ◽  
Author(s):  
Morgan M. Brent
Keyword(s):  
Bacterial Flora ◽  
Phosphate Buffer Solution ◽  
Potassium Phosphate ◽  
Potassium Phosphate Buffer ◽  
Buffer Solution ◽  
E Coli ◽  
Potassium Phosphate Buffer Solution ◽  
Factor Governing ◽  
Proportional Incidence ◽  
Peptone Broth

The amoebae of Tetramitus rostratus growing with Escherichia coli were inoculated into a yeast peptone broth and a potassium phosphate buffer solution, and flagellate formation was studied. In both, the numbers of flagellates formed and their proportional incidence increased with the number of amoebae inoculated. In buffer the numbers of flagellates reached a peak at 10 hours, and in broth at 23 hours.Comparisons between the buffer and broth, using the same inoculum, indicated that population density is only one factor governing flagellate formation, since this transformation was greater in buffer for a given population.Replacement of E. coli with four other monoxenic associates indicated that bacterial flora makes little difference in buffer on flagellate transformation, as flagellates were formed with all four genera. A search for a "flagellating substance" produced in the medium or within the cells was not successful.

scholarly journals In-house validation method for quantification of amoxicillin in medicated feedingstuffs with the use of HPLC-DAD technique

2020 ◽  
Vol 64 (3) ◽  
pp. 433-438
Author(s):  
Ewelina Patyra ◽  
Krzysztof Kwiatek
Keyword(s):  
Phosphate Buffer ◽  
High Performance ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Potassium Phosphate ◽  
High Performance Liquid Chromatographic ◽  
Array Detector ◽  
Buffer Solution ◽  
Limit Of Quantification ◽  
Potassium Phosphate Buffer Solution

AbstractIntroductionA high-performance liquid chromatographic–diode array detector (HPLC-DAD) method for the determination of amoxicillin in medicated feedingstuffs was developed and validated. The method was used to investigate the quality requirements of animal feedingstuffs (declared content of active substance and feed homogeneity).Material and MethodsTwo-gram samples were extracted by potassium phosphate buffer solution. Extracts were filtered and directly analysed by HPLC-DAD without further clean-up. Amoxicillin was separated by acetonitrile and 0.01M phosphate buffer (pH 5.0) on a Phenomenex Luna C18 column.ResultsThis method provided average recoveries of 76.1 to 81.6% with coefficients of variation (CV, %) for repeatability and reproducibility in the ranges of 3.7–7.2% and 5.3–7.6%, respectively. The limit of detection was 51.2 mg/kg and limit of quantification was 103.0 mg/kg.ConclusionThe method was successfully validated and proved to be efficient, precise, and useful for quantification of amoxicillin in medicated feedingstuffs.

Detection of Hepatitis a Virus in Drinking Water by Enzyme -Immunoassay Using Ultracentrifugation for Virus Concentration

1985 ◽  
Vol 17 (10) ◽  
pp. 39-41 ◽  
Author(s):  
A. Schnattinger
Keyword(s):  
Membrane Filtration ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Phosphate Buffer Solution ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Concentration ◽  
Buffer Solution ◽  
Solution Ph ◽  
Two Stage

Ten litres of tapwater were seeded with 200 µl (8×108 HAV particles) of a commercial (Organon Teknika) suspension of hepatitis A virus. Following WALTER and RÜDIGER (1981), the contaminated tapwater was treated with a two-stage technique for concentration of viruses from solutions with low virus titers. The two-stage technique consists of aluminium hydroxideflocculation (200 mg/l Al2(SO4)3. 18 H2O, pH 5,4-5,6) as first stage, the second stage of a lysis of aluminium hydroxidegel with citric acid/sodium citrate-buffer (pH 4,7; 1 ml/l sample), separation of viruses from the lysate by ultracentrifugation and suspension in 1 ml phosphate buffer solution (pH 7,2). A commercial solid phase enzyme-linked immunosorbent assay (ELISA) was used for the detection of HAV. HAV was detecterl in the 10.000:1 concentrates, but not in the seeded 101 samples. Approximately 4×108 of the inoculated 8×108 HAV particles were found in the 1 ml concentrates. The efficiency of detection is about 50%, the virus concentration 5000-fold. Although the percentage loss of HAV in comparison with concentration by means of membrane filtration is similar, the ultracentrifugation method yields a larger sample/concentrate ratio, so that smaller amounts of HAV can be detected more efficiently because of the smaller end-volume.

Non-enzymatic determination of purine nucleotides using a carbon dot modified glassy carbon electrode

2019 ◽  
Vol 11 (30) ◽  
pp. 3866-3873 ◽  
Author(s):  
R. Karthikeyan ◽  
D. James Nelson ◽  
S. Abraham John
Keyword(s):  
Glassy Carbon ◽  
Low Cost ◽  
Phosphate Buffer Solution ◽  
Purine Nucleotides ◽  
Buffer Solution ◽  
Solution Ph ◽  
Carbon Dot ◽  
Enzymatic Determination ◽  
Sensitive Determination

Selective and sensitive determination of one of the purine nucleotides, inosine (INO) using a low cost carbon dot (CD) modified glassy carbon (GC) electrode in 0.2 M phosphate buffer solution (pH 7.2) was demonstrated in this paper.

scholarly journals Electro-Polymerized Titan Yellow Modified Carbon Paste Electrode for the Analysis of Curcumin

Surfaces ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 191-204
Author(s):  
Edwin S. D’Souza ◽  
Jamballi G. Manjunatha ◽  
Chenthattil Raril ◽  
Girish Tigari ◽  
Huligerepura J. Arpitha ◽  
...  
Keyword(s):  
Carbon Paste Electrode ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
Buffer Solution ◽  
Solution Ph ◽  
Real Sample Analysis ◽  
Titan Yellow ◽  
Paste Electrode

A modest, efficient, and sensitive chemically modified electrode was fabricated for sensing curcumin (CRC) through an electrochemically polymerized titan yellow (TY) modified carbon paste electrode (PTYMCPE) in phosphate buffer solution (pH 7.0). Cyclic voltammetry (CV) linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV) approaches were used for CRC detection. PTYMCPE interaction with CRC suggests that the electrode exhibits admirable electrochemical response as compared to bare carbon paste electrode (BCPE). Under the optimized circumstances, a linear response of the electrode was observed for CRC in the concentration range 2 × 10−6 M to 10 × 10−6 M with a limit of detection (LOD) of 10.94 × 10−7 M. Moreover, the effort explains that the PTYMCPE electrode has a hopeful approach for the electrochemical resolution of biologically significant compounds. Additionally, the proposed electrode has demonstrated many advantages such as easy preparation, elevated sensitivity, stability, and enhanced catalytic activity, and can be successfully applied in real sample analysis.

Controlled Release of Active Substance from Biodegradable Copolymer Matrix

2006 ◽  
Vol 510-511 ◽  
pp. 798-801
Author(s):  
Hyung Suk So ◽  
Hyun Chul Shin ◽  
Beom Suk Kim ◽  
Yeong Seok Yoo
Keyword(s):  
Methylene Blue ◽  
Active Substance ◽  
Phosphate Buffer Solution ◽  
Ultra Violet ◽  
Hydroxyl Groups ◽  
Buffer Solution ◽  
Solution Ph ◽  
Effective Discharge ◽  
Constant Rate ◽  
Long Time

The purpose of this study is to develop a new system to control effective discharge of active substances such as agricultural chemicals. To synthesize a naturally dissolvable polymer; ε-caprolactone and diglycolide were copolymerized with ethylene glycol as an initiator to produce macrodiol. As macrodiol has hydroxyl groups in both ends, they are modified with methacryloyl chloride for photochemical networking. After standard macromonomer produced by this procedure was physically mixed with methylene blue, it was networked with ultra-violet rays to be filmed. This film is naturally dissolvable and hydrolytic. As a result of hydrolytic test with a crosslinked structure of 10 % methylene blue, it decreased by 9 % for seven weeks in 37 °C phosphate buffer solution (pH = 7). Thus, we verified that active substance can be discharged from a crosslinked structure for a long time at a constant rate under room temperature.

OPTIMISATION AND VALIDATION OF HPLC METHOD FOR SIMULTANEOUS QUANTIFICATION OF RIFAMPICIN, ISONIAZID, PYRAZINAMIDE, AND ETHAMBUTOL HYDROCHLORIDE IN ANTI-TUBERCULOSIS 4-FDC TABLET

2015 ◽  
Vol 77 (1) ◽  
Author(s):  
Sholihul Khoiri ◽  
Sudibyo Martono ◽  
Abdul Rohman
Keyword(s):  
High Performance ◽  
Phosphate Buffer Solution ◽  
Gradient Elution ◽  
Hplc Method ◽  
Fixed Dose ◽  
Buffer Solution ◽  
Solution Ph ◽  
Combination Tablet ◽  
Simultaneous Quantification ◽  
Dose Combination

High-performance liquid chromatography (HPLC) method has been developed and validated for the simultaneous quantification of four components, namely rifampicin (RIF), isoniazid (INH), pyrazinamide (PYR), and ethambutol hydrochloride (ETM), contained in anti-tuberculosis drugs in fixed dose combination tablet (4-FDC). In order to increase the sensitivity of EMB, the pre-column derivatization technique with phenethyl isocyanate (PEIC) was carried out. The separation was accomplished using Waters Symmetry C8 (250× 4.6 mm i.d.; 5 μm) at 30oC. The mobile phase used was a mixture of acetonitrile and 20 mM phosphate buffer solution (pH 6.8) containing triethylamine and delivered at 1.5 mL/minute using gradient elution. TheUV detector was set at 210 nm. The method was validated in terms of selectivity, linearity, accuracy, precision, detection limit, quantification limit, and robustness according to International Conference on Harmanization (ICH). The optimized method is succcesfully used for quantitative analysis of RIF, INH, PYR and ETM in 4-FDC tablets. The level of these drugs in 4-FDC tablets were in accordance to that specified in Indonesian pharmacopeia.

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