scholarly journals Derivative Spectrophotometric Methods for the Analysis and Stability Studies of Colistin Sulphate

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammed Mutasim Elimam ◽  
Shaza Wagiealla Shantier ◽  
Elrasheed Ahmed Gadkariem ◽  
Magdi Awadalla Mohamed
Keyword(s):  
Stability Study ◽  
Alkaline Media ◽  
Second Derivative ◽  
Spectrophotometric Methods ◽  
Different Temperatures ◽  
The Stability ◽  
Second Derivative Spectra ◽  
Rate Profile ◽  
Second Derivative Method

Simple spectrophotometric methods were developed for the quantitative determination of colistin sulphate in bulk and dosage forms. The methods were based on the measurement of first and second derivative spectra of colistin sulphate at 298 nm and 318 nm, respectively. Beer’s law was obeyed in the concentration range 800–4000 IU/mL with good correlation coefficient (not less than 0.998) for both methods. The developed first derivative spectrophotometric method was then selected to study the degradation behavior of colistin sulphate in alkaline media at different temperatures as the second derivative method failed to give reproducible results for the stability study. The pH-rate profile indicates a first-order dependence of the degradation rate on [OH−] at pH ranging between 8 and 11. The obtained results for the photochemical study reflected photostability of colistin sulphate.

Different Spectrophotometric and Chromatographic Methods for Determination of Mepivacaine and Its Toxic Impurity

2017 ◽  
Vol 100 (5) ◽  
pp. 1392-1399 ◽  
Author(s):  
Nada S Abdelwahab ◽  
Nehal F Fared ◽  
Mohamed Elagawany ◽  
Esraa H Abdelmomen
Keyword(s):  
Particle Size ◽  
Stationary Phase ◽  
Second Derivative ◽  
Spectrophotometric Measurement ◽  
Spectrophotometric Methods ◽  
Derivative Method ◽  
Tlc Plates ◽  
Second Derivative Method ◽  
Developing System

Abstract Stability-indicating spectrophotometric, TLC-densitometric, and ultra-performance LC (UPLC) methods were developed for the determination of mepivacaine HCl (MEP) in the presence of its toxic impurity, 2,6-dimethylanaline (DMA). Different spectrophotometric methods were developed for the determination of MEP and DMA. In a dual-wavelength method combined with direct spectrophotometric measurement, the absorbancedifference between 221.4 and 240 nm was used for MEPmeasurements, whereas the absorbance at 283 nm was used for measuring DMA in the binary mixture. In the second-derivative method, amplitudes at 272.2 and 232.6 nm were recorded and used for the determination of MEP and DMA, respectively. The developed TLC-densitometric method depended on chromatographic separation using silica gel 60 F254 TLC plates as a stationary phase and methanol–water–acetic acid (9 + 1 + 0.1, v/v/v) as a developing system, with UV scanning at 230 nm. The developed UPLC method depended on separation using a C18 column (250 × 4.6 mm id, 5 μm particle size) as a stationary phase and acetonitrile–water (40 + 60, v/v; pH 4 with phosphoric acid) as a mobilephase at a flow rate of 0.4 mL/min, with UV detection at 215 nm. The chromatographic run time was approximately 1 min. The proposed methods were validated with respect to International Conference on Harmonization guidelines regarding precision, accuracy, ruggedness, robustness, and specificity.

The Stability Study of Thermodynamic Parameters of Sorption of Light Hydrocarbons on Poly [Trimethylsilyl (Propyn-1)] at Different Temperatures

2019 ◽  
Vol 57 (9) ◽  
pp. 778-783
Author(s):  
V E Shiryaeva ◽  
A A Korolev ◽  
T P Popova ◽  
A Y Kanateva ◽  
A A Kurganov
Keyword(s):  
Stationary Phase ◽  
Thermodynamic Parameters ◽  
Heating Temperature ◽  
Chromatographic Determination ◽  
Stability Study ◽  
Light Hydrocarbons ◽  
Different Temperatures ◽  
Entropy Factor ◽  
The Stability

Abstract Chromatographic determination of the thermodynamic parameters of sorption for light hydrocarbons retention on a stationary phase based on poly [trimethylsilyl (propyn-1)] (PTMSP) was performed and the effect of column preheating at temperatures up to 260°C on the retention of analytes was investigated. It was shown that heating the column to 130°C does not affect the retention of the analytes. At temperatures above 130°C, the gradual decrease of the retention of analytes on PTMSP stationary phase is observed. The process is non-selective and proceeds at the same extent for all the studied hydrocarbons, regardless of the size and geometry of the molecule. Values of enthalpy and entropy of sorption of light hydrocarbons are determined for the original column and after its aging at 200°C. The enthalpy of sorption of the analytes at the PTMSP phase is practically independent on the heating temperature of the PTMSP phase, whereas the loss of entropy increases after heating. The increase of the entropy factor after the heating of the PTMSP stationary phase is associated with its aging and is confirmed by the construction of compensation functions for treated and untreated columns.

scholarly journals VALIDATED SPECTROPHOTOMETRIC METHODS FOR THE ESTIMATION OF CINNARIZINE IN BINARY MIXTURE WITH PARACETAMOL IN BULK AND TABLETS

2021 ◽  
pp. 161-166
Author(s):  
AHMED M AL-GHANI ◽  
ANES AM THABET
Keyword(s):  
Quality Control ◽  
Second Derivative ◽  
Derivative Spectrum ◽  
Zero Crossing ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
Derivative Method ◽  
Analytical Tools ◽  
Second Derivative Method

Objectives: The aim of this work was to develop and validate new, simple, accurate, and selective spectrophotometric methods (derivative and derivative ratio spectrophotometric methods) for the determination of these drugs. These methods can be used as analytical tools in routine examination in quality control laboratories. Methods: The first method was derivative method in which the first derivative method (1D) for determination of PCM and the second derivative method (2D) for determination of CIN. The second method was the first derivative ratio spectrophotometric method (1DD) for determination of CIN and PCM. Results: In first method, the first derivative spectrum (1D) of PCM where PCM was determined by measuring the amplitude of the valley at 235 nm while CIN showed zero crossing spectrum, and the second derivative spectrum (2D) of CIN where CIN was determined by measuring the amplitude of the peak at 287.5 nm while PCM showed a zero value. In the second method, the first derivative ratio spectrophotometry (1DD) for CIN and PCM determination, where the amplitude at 290 and 291 nm, was selected for the determination of CIN and PCM, respectively. Conclusions: The developed methods were applied for the determination of the cited drugs in tablets containing binary drug mixture. The methods are simple and precise and can be used for routine analysis of the labeled drugs in combined dosage forms in quality control laboratories.

scholarly journals Charge Transfer Complexes of Ketotifen with 2,3-Dichloro-5,6-dicyano-p-benzoquinone and 7,7,8,8-Tetracyanoquodimethane: Spectroscopic Characterization Studies

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2039
Author(s):  
Gamal A. E. Mostafa ◽  
Ahmed Bakheit ◽  
Najla AlMasoud ◽  
Haitham AlRabiah
Keyword(s):  
Charge Transfer ◽  
Spectroscopic Characterization ◽  
Molar Ratio ◽  
Charge Transfer Complexes ◽  
Physical Parameters ◽  
Spectrophotometric Methods ◽  
Theoretical Approaches ◽  
The Stability ◽  
Ct Complexes

The reactions of ketotifen fumarate (KT) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π acceptors to form charge transfer (CT) complexes were evaluated in this study. Experimental and theoretical approaches, including density function theory (DFT), were used to obtain the comprehensive, reliable, and accurate structure elucidation of the developed CT complexes. The CT complexes (KT-DDQ and KT-TCNQ) were monitored at 485 and 843 nm, respectively, and the calibration curve ranged from 10 to 100 ppm for KT-DDQ and 2.5 to 40 ppm for KT-TCNQ. The spectrophotometric methods were validated for the determination of KT, and the stability of the CT complexes was assessed by studying the corresponding spectroscopic physical parameters. The molar ratio of KT:DDQ and KT:TCNQ was estimated at 1:1 using Job’s method, which was compatible with the results obtained using the Benesi–Hildebrand equation. Using these complexes, the quantitative determination of KT in its dosage form was successful.

scholarly journals STABILITY STUDY OF AMLODIPINE BESYLATE AND BISOPROLOL FUMARATE IN AQUEOUS SOLUTIONS

2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Irena Kasagić Vujanović ◽  
Dijana Jelić ◽  
Vesna Antunović ◽  
Biljana Jančić Stojanović ◽  
Darko Ivanović
Keyword(s):  
Relevant Information ◽  
Pharmaceutical Product ◽  
Stability Study ◽  
Amlodipine Besylate ◽  
Time Intervals ◽  
Constant Rate ◽  
Different Temperatures ◽  
The Media ◽  
Two Temperatures ◽  
The Stability

Valuable information concerning stability of compounds can be obtained by using different media (water, hydrochloric acid or sodium hydroxide) for dissolution of active pharmaceutical substances. Furthermore, additional knowledge is gained by performing experiments at different temperatures. This research paper deals with the stability of amlodipine besylate and bisoprolol fumarate in different media at different temperatures, whereby certain conclusions are drawn. For stability assessment, chemical kinetics approach was used, and constant rate (k), half-time (t1/2) and activation energy (Ea) were used for prediction of compound stability degree. The stability of amlodipine besylate and bisoprolol fumarate were tested, both separately and in mixture, in water and in 0.01M HCl. All the investigated solutions were treated at two temperatures 25° and 70°C at the following time intervals: 0, 1 h, 24 h, 48 h and 72 h. Hydrophilic Interaction Liquid Chromatography – HILIC method, previously developed and validated, was used. On the basis of obtained results it was concluded that amlodipine-besylate was more stable in water than in acid medium, more stable in mixture rather than individually and more stable at lower temperatures. This was confirmed by the obtained values of monitored parameters: amlodipine besylate Ea = 30.68 kJ mol-1, k (25 °C) = 0.000333 mM h-1, k (70 °C) = 0.00169 mM h-1; amlodipine besylate in mixture Ea = 42,414 kJ mol-1, k (25 °C) = 1.27∙10-4 mM h-1, k (70 °C) = 0.0012 mM h-1. Based on the obtained approximate Ea value for bisoprolol fumarate in acid (59 kJ mol-1) and in water (56 kJ mol-1), bisoprolol fumarate showed excellent stability against the media in which it was studied. On the other hand, the temperature had a significant effect on the stability of bisoprolol fumarate. These results provide the relevant information about the stability of the tested active substances, and may be of importance during the development of an appropriate pharmaceutical product. A bigger influence on the stability of bisoprolol fumarate had a temperature effect.

Multi-wavelength analyses of second-derivative spectra for rapid determination of acetaminophen in serum.

1988 ◽  
Vol 34 (6) ◽  
pp. 1119-1121 ◽  
Author(s):  
B Dingeon ◽  
M A Charvin ◽  
M T Quenard ◽  
H Thome
Keyword(s):  
Phosphate Buffer ◽  
Rapid Determination ◽  
Turnaround Time ◽  
Second Derivative ◽  
Derivative Spectra ◽  
Multi Wavelength ◽  
Precision And Accuracy ◽  
Second Derivative Spectra ◽  
Method Of Extraction

Abstract Measurement of acetaminophen by analysis of the second derivative of its spectrum is specific and sensitive. The method of extraction and the use of just one phosphate buffer as reagent makes this method very convenient. Readings are reliable from 10 to 1500 mg/L. A turnaround time of 20 min makes this method well suited for emergency cases. Precision and accuracy of the method are presented. Results are not biased by interferences, not even from N-acetylcysteine.

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