The sodium 5-butyl-1,2-diphenyl-6-oxo-1,6-dihydropyrimidine-4-olate quantitative content determination in a standard sample

Introduction. The standard samples (SS) use is a necessary condition for the medicines' quality control implementation. Their development is an urgent problem for the pharmaceutical industry, especially for new biologically active compounds that can be further used as pharmaceuticals.Aim. This work aim is to establish the 5-butyl-1,2-diphenyl-6-oxo-1,6-dihydro pyrimidone-4-olate sodium quantitative content, for which anti-inflammatory and analgesic activity was previously proven, in a standard sample.Materials and methods. This work aim is to establish the 5-butyl-1,2-diphenyl-6-oxo-1,6-dihydro pyrimidone-4-olate sodium quantitative content, for which anti-inflammatory and analgesic activity was previously proven, in a standard sample. The main method for establishing a substance quantitative content in the SS is the material balance method. The water determination was carried out according to K. Fisher's method (semimicro method). Sulphated ash was determined according to the XIV edition Russian Federation State Pharmacopoeia General Pharmacopoeia Monograph "Sulphated ash". Related impurities and their content were assessed using the HPLC method on a Flexar liquid chromatograph equipped with a diode array detector (Perkin Elmer, USA). The residual solvents' determination was carried out by the headspace method using a gas chromatograph GC-2010Plus Shimadzu with a flame ionization detector. As an additional method for establishing the main component quantitative content, acidimetric titration with the equivalence point potentiometric indication was carried out.Results and discussion. The percentage was determined for the following indicators: water, residual organic solvents, related impurities, sulphated ash. Using the material balance method, it was found that the 5-butyl-1,2-diphenyl-6-oxo-1,6-dihydropyrimidin-4-olate sodium percentage in a standard sample is 96.01 ± 0.50 %. It was found by acidimetric titration that the 5-butyl-1,2-diphenyl-6-oxo 1,6-dihydropyrimidin- 4-olate sodium quantitative content in SS is 95.12 ± 0.02 %. The difference in the certified value can be explained by the fact that during titration, the SS aciform is released, which precipitates in an aqueous medium and contributes to a shift in the equilibrium and pH value. Consequently, the equivalence point is reached somewhat earlier. However, the data are practically comparable, but it is necessary to use the value obtained by the material balance method.Conclusion. A standard sample certification parameters were determined: water content, residual organic solvents, sulphated ash, related impurities. The main component quantitative content was determined using the material balance method and titrimetry (acidimetry with the equivalence point potentiometric indication).

USING POTENTIOMETRIC ACID-BASE TITRATION TO DETERMINE PKA FROM MANGOSTEEN PERICARPS EXTRACT

One of the uses of acid-base indicators is to show the end point of the titration, so the accurate determination of acidity constant and pH range of indicators needs to be done. This study aims to determine the acidity constant (pKa) of mangosteen pericarp extract and its accuracy as an indicator of acid-base titration. Determination of pKa was done by a simple potentiometric titration method. The titration data were plotted in three graphs, i.e., pH, ΔpH/ΔV (the (the first derivative), and Δ2pH/ΔV2 (the second derivative) versus titrant volume to determine the equivalence point of the titration. The accuracy test was carried out by comparing the volume of oxalic acid used to titrate NaOH solution using the indicator of mangosteen pericarp extract and phenolphthalein indicator. The result showed that the equivalence point was found on the titrant volume of 8.6 mL and a measured pH of 9.84. so the pKa value of mangosteen pericarp extract was 7.20, and the pH range was 6.20 to 8.20. the average volume of oxalic acid used to titrate 5 mL of NaOH using phenolphthalein as the indicator was 5.2 mL while the titration used mangosteen pericarp extract was 5.23 mL. The accuracy of mangosteen pericarp extract was 99.42%. By the result, it can be concluded that potentiometric titration can be used as a simple way to determine the acidity constant of mangosteen pericarp extract. Moreover, the mangosteen pericarp extract can be used as an alternative acid-base titration indicator to substitute the common acid-base titration in the laboratory.

Antibacterial activity of the sambiloto leaf extracts (Andrographis paniculata) to Bacillus cereus and Pseudomonas aeruginosa

Mardiana RN, Handayani N. 2016. Antibacterial activity of the sambiloto leaf extracts (Andrographis paniculata) to Bacillus cereus and Pseudomonas aeruginosa. Biofarmasi 14: 19-24. The purpose of this research was to evaluate the antibacterial activity of sambiloto ( Andrographis paniculata Nees. ) extract against bacterial Bacillus cereus and Pseudomonas aeruginosa. Some research had proven sambiloto leaf extract evident had antibacterial activity to bacteria Staphylococcus aureus. The sample of sambiloto leaf was macerated using 70% ethanol, and the extract was concentrated using rotary evaporator. The antibacterial activity was evaluated by diffusion method. Antibacterial potency of the extract was compared with by Amoxicillin made default curve among logarithm concentrates to constraining diameter (mm), then accounted by its equivalence point. Ethanol extract of sambiloto leaf had antibacterial activity to B. cereus and P. aeruginosa. Minimum Inhibitory Concentration (MIC) of 12,5% against B. cereus and P. aeruginosa. The potential antibacterial activity of sambiloto leaf extract was 0,2% for B. cereus and 0.3% for P. aeruginosa; as compared with Amoxicillin. This, potential antibacterial activity of sambiloto leaf extract to the two tested bacteria was much smaller than that of Amoxicillin synthetic antibiotic.

Silver Cation Coordination Study to AsW9 Ligand – A Trilacunar Arsenotungstate Compound

Objective: The main objective of this research is to find the coordination ratio between AsW9 and Ag+, as a preliminary study for synthesizing a new silver-arsenotungstate complex. Material and method: The ligand:cation molar ratio in complexes was determined by conductometric and potentiometric titrations of AsW9 with silver salts: CH3COOAg, AgNO3. Results: The ratio was obtained from the inflexion points of the curves when molar ratio was plotted versus conductivity, or from the equivalence point when silver added volume was plotted versus pH value. Each graphic shows one point of inflexion corresponding to 1:1.54 ratio of AsW9:Ag+. In the same manner, the equivalent volumes determined by graphical method gave the ratio 1:1.53. The spectral results confirmed that a AsW9:Ag+ complex was formed since the ligand absorption maxima values have been changed from 190 nm to 197 nm in the case of using AgNO3 and 196 nm for CH3COOAg corresponding to the W=Od bond, and from 246.5 nm to 274 nm (AgNO3) and 270 nm (CH3COO-Ag+) for the W-Ob,c-W bond. Conclusions: Silver cation exhibit a preference for AsW9 in a ratio of 3 to 2. This ratio can be associated to a sandwich type arrangement, with two trilacunary Keggin building blocks incorporating 3 metal cations in a tetrahedral geometry.

Insight into the deprotonation at the half-equivalence point of (thio)amido-benzimidazoles in the presence of anions

Three crystallographic structures highlight the acid–base half-equivalence point of hydrogen-bond donor (thio)amido-benzimidazoles induced by fluoride or benzoate salts with concomitant hydrogen-bonding and deprotonation as a merged synergic process.

Detecting levels of polyquaternium-10 (PQ-10) via potentiometric titration with dextran sulphate and monitoring the equivalence point with a polymeric membrane-based polyion sensor

This manuscript reports a novel and facile method for PQ-10/SLS separation and subsequent PQ-10 quantification via potentiometric titration.