Microscale Titrimetric and Spectrophotometric Methods for Determination of Ionization Constants and Partition Coefficients of New Drug Candidates

1998 ◽  
Vol 87 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Michael E. Morgan ◽  
Kui Liu ◽  
Bradley D. Anderson
1988 ◽  
Vol 53 (2) ◽  
pp. 258-268 ◽  
Author(s):  
Brígida Santana ◽  
María J. Sánchez ◽  
Juan J. Arias ◽  
Francisco García-Montelongo

2-(2’-Thiazolylazo)-4,6-dimethylphenol (TADMP) and 2-(4’,5’-dimethyl-2’-thiazolylazo)-4,6-dimethylphenol (DMTADMP) have been synthesized and their ionization constants determined by spectrophotometric methods and graphical and numerical calculation methods. Both reagents form UO2R+ and UO2R2 complexes with uranium (TADMP: log β101 = 9.18 ± 0.02, log β102 = 17.64 ± 0.01; DMTADMP: log β101 = 8.38 ± 0.02, log β102 = 18.78 ± 0.14) in a 40% (v/v) ethanol-water medium at I = 0.25 (NaClO4). An extraction-spectrophotometric method for the determination of 1.35-9.45 ppm uranium based on its extraction into toluene with TADMP from a pH 6.5 buffered medium has been developed ( ε = 1.6 . 104 l mol-1 cm-1 at 580 nm), and applied to its determination in sulphuric acid leaching residues.


Author(s):  
Abbas Shebeeb Al-kadumi ◽  
Sahar Rihan Fadhel ◽  
Mohammed Abdullah Ahmed ◽  
Luma Amer Musa

We proposed two simple, rapid, and convenient spectrophotometric methods are described for the determination of Amoxicillin in bulk and its pharmaceutical preparations. They are based on the measurement of the flame atomic emission of potassium ion (in first method) and colorimetric determination of the green colored solution for manganite ion at 610 nm formed after reaction of Amoxicillin with potassium permanganate as oxidant agent (in the second method) in basic medium. The working conditions of the methods were investigated and optimized. Beer's law plot showed a good correlation in the concentration range of 5-45 μg/ml. The detection limits and relative standared deviations were (2.573, 2.814 μg/ml) (2.137, 2.498) for the flame emission photometric method and (1.844, 2.016 μg/ml) (1.645,1.932) for colorimetric methods for capsules and suspensions respectively. The methods were successfully applied to the determination of Amoxicillin in capsules and suspensions, and the obtained results were in good agreement with the label claim. No interference was observed from the commonly encountered additives and expectancies.


2018 ◽  
Vol 25 (20) ◽  
pp. 2304-2328 ◽  
Author(s):  
Lishu Wang ◽  
Jungfeng Wang ◽  
Juan Liu ◽  
Yonghong Liu

Due to the importance of nature as a source of new drug candidates, the purpose of this article is to emphasize the marine natural products, which exhibit antitubercular activity, published between January 2000 and May 2016, with 138 quotations to 250 compounds obtained from marine resources. These metabolites are organized by chemical constitution and named as simple alkyl lipids derivatives, aromatics derivatives, peptides, alkaloids, terpenoids, steroids, macrolides, and polycyclic polyketides.


2019 ◽  
Vol 22 (8) ◽  
pp. 509-520
Author(s):  
Cauê B. Scarim ◽  
Chung M. Chin

Background: In recent years, there has been an improvement in the in vitro and in vivo methodology for the screening of anti-chagasic compounds. Millions of compounds can now have their activity evaluated (in large compound libraries) by means of high throughput in vitro screening assays. Objective: Current approaches to drug discovery for Chagas disease. Method: This review article examines the contribution of these methodological advances in medicinal chemistry in the last four years, focusing on Trypanosoma cruzi infection, obtained from the PubMed, Web of Science, and Scopus databases. Results: Here, we have shown that the promise is increasing each year for more lead compounds for the development of a new drug against Chagas disease. Conclusion: There is increased optimism among those working with the objective to find new drug candidates for optimal treatments against Chagas disease.


2020 ◽  
Vol 16 (2) ◽  
pp. 190-195 ◽  
Author(s):  
Süleyman Ediz ◽  
Murat Cancan

Background: Reckoning molecular topological indices of drug structures gives the data about the underlying topology of these drug structures. Novel anticancer drugs have been leading by researchers to produce ideal drugs. Materials and Methods: Pharmacological properties of these new drug agents explored by utilizing simulation strategies. Topological indices additionally have been utilized to research pharmacological properties of some drug structures. Novel alkylating agents based anticancer drug candidates and ve-degree molecular topological indices have been introduced recently. Results and Conclusion: In this study we calculate ve-degree atom-bond connectivity, harmonic, geometric-arithmetic and sum-connectivity molecular topological indices for the newly defined alkylating agents based dual-target anticancer drug candidates.


2020 ◽  
Vol 16 ◽  
Author(s):  
Mamdouh R. Rezk ◽  
Mina Wadie ◽  
Soheir A. Weshahy ◽  
Mahmoud A. Tantawy

Background: Alfuzosin is recently co-formulated with solifenacin for relieving two coincident urological diseases, namely; benign prostate hyperplasia and overactive bladder Objective: Herein, green, simple and rapid spectrophotometric methods were firstly developed for simultaneous determination of the two cited drugs in their co-formulated pharmaceutical capsule Methods: Alfuzosin, which is the major component in the dosage form, was directly assayed at its extended wavelength at 330.0 nm. The challenging spectrum of the minor component, solifenacin, was resolved by five spectrophotometric methods, namely; dual wavelength (DW) at 210.0 & 230.0 nm, first derivative (1D) at 222.0 nm, ratio difference (RD) at 217.0 - 271.0 nm , derivative ratio (1DD) at 223.0 and mean centering of ratio spectra (MC) at 217.0 nm Results: The Proposed methods were successfully validated as per ICH guidelines. Alfuzosin showed linearity over the range of 4.0 - 70.0 μg/mL, while that of solifenacin were 4.0 - 50.0 μg/mL for DW, 2.0 - 70.0 μg/mL for 1D and RD methods, 1.0 - 70.0 μg/mL for 1DD and 4.0 - 70.0 μg/mL for MC method. Statistical comparison with their official ones showed no noticeable differences. The methods showed good applicability for assaying drugs in their newly combination. Besides eco-scale, the greenness profile of the methods was assessed and compared with the reported spectrophotometric one via the newest metric tool; green analytical procedure index (GAPI). Conclusions: The proposed methods are superior in not only being smart, accurate, selective, robust and time-saving, but also in using distilled water as an eco-friendly and cheap solvent


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