Selective analysis of mutual displacement effects at the primary binding sites of phenoxymethylpenicillin and cephalothin bindings to human serum albumin

Cephalothin: Review of Characteristics, Properties and Status of Analytical Methods

BACKGROUND

Cephalothin (CET), a first generation cephalosporin, is the most efficient cephalosporin against resistant microorganisms. Many studies found in literature and pharmacopeias proposes analytical methods and, as most commonly, HPLC and microbiological assays.

OBJECTIVE

This paper shows a brief review of analytical method to quantify CET with a green analytical chemistry approach.

METHODS

The research data were collected from the literature and official compendia.

RESULTS

Most of the analytical methods to determine CET were performed by HPLC and agar diffusion in pharmaceuticals, blood, urine or water. Other analytical methods were found, as UV, Vis, iodometry, fluorimetry, IR/Raman, electrochemical among others, but, in less quantity. One important aspect is that these methods use organic and toxic solvents like methanol and acetonitrile, and only about 4% of the methods found uses water as solvent.

CONCLUSIONS

In this way, researches about analytical methods focused on green analytical chemistry for CET are of great importance and very relevant to optimize its analysis in pharmaceutical industries and to guarantee the quality of the product. More than just the development of new techniques it is possible to enhance of the ones that already exists applying the green analytical chemistry principles. In this way, it will be possible to reduce the environment impacts caused by these analytical procedures.

HIGHLIGHTS

This work shows a brief review of literature and pharmacopeias of analytical methods to quantify CET. Its quality control can be updated to meet the needs of current analytical chemistry and to fit into sustainable and eco-friendly analyzes.

Review for Analytical Methods for the Determination of Sodium Cephalothin

Infections are the second leading cause of global morbidity and mortality, therefore it is highly important to study the antimicrobial agents such as cephalosporins. Cephalothin, an antimicrobial agent that belongs to the class of cephalosporins, has bactericidal activity and it is widely used in the Brazilian health system. In literature, some analytical methods are found for the identification and quantification of this drug, which are essential for its quality control, which ensures maintaining the product characteristics, therapeutic efficacy and patient's safety. The aim of this article is to review the available information on analytical methods for cephalothin. Thus, this study presents a literature review on cephalothin and the analytical methods developed for the analysis of this drug in official and scientific papers. It is essential to note that most of the developed methods used toxic and hazardous solvents, which makes necessary industries and researchers choose to develop environmental-friendly techniques, which will contribute to the harmonization of science, human, and environmental health.

Stereoselective binding of carbenicillin epimers to human serum albumin

Binding of carbenicillin (CBPC) epimers to human serum albumin (HSA) was found to be stereoselective. Epimer-epimer interaction was also observed in the binding to HSA. There were at least three binding sites on HSA for CBPC epimers, one of which (stereoselective site) was more in favor of S-CBPC than R-CBPC. At the stereoselective site, the binding constant of S-CBPC was approximately 4-fold greater than that of R-CBPC. The affinities to other binding sites (non-stereoselective sites) were similar between the epimers, and the affinity of S-CBPC of the non-stereoselective sites was much smaller than that for the stereoselective site. R-CBPC and S-CBPC appeared to displace each other at all the binding sites, i.e., the binding of the epimers was competitive at the non-stereoselective sites as well as at the stereoselective site. By using site marker ligands, it was revealed that CBPC epimers may bind to Site I (warfarin binding site), but not to Site II (diazepam binding site). A binding model with an assumption of competitive interactions at all the binding sites simulated the binding characteristics of CBPC epimers fairly well.

Binding of (+)- and (-)-isomers and racemate of etomoxir to human serum albumin and effect of stearic acid and stanozolol

Binding of (+)- and (-)-isomers and the racemate of sodium 2[6-(4-chlorophenoxy)-hexyl]-oxiran-2-carboxylate dihydrat (etomoxir) to the human serum albumin (HSA) was studied by the gel filtration method. The experimental results are presented graphically using the method of Scatchard. Measurements revealed the following data on the binding: (a) for either of the isomers there are two independent and nonequivalent classes of binding sites on the HSA molecule; (b) the binding constants calculated for both isomers were of the same order of magnitude (K1/n approximately 20 x 10(5) L.mol-1 for the concentration range 3.48-4.0 x 10(-5) mol.L-1, and K2/n approximately 2 x 10(5) L.mol-1 for the concentration range 4.28-10 x 10(-5) mol.L-1, for the high and low affinity binding sites, respectively); (c) statistically significant difference (p < or = 0.05) between the low affinity binding constant estimated for the (+)-isomer K2 = 1.9 +/- 0.1 x 10(5) L.mol-1) compared with the constants evaluated for the (-)-isomer and racemic etomoxir (2.6 +/- 0.1 and 2.9 +/- 0.2 x 10(5) L.mol-1, respectively); and (d) both isomers are bound into a high extent to the HSA molecule (i.e., at a ligand concentration of 3.48 x 10(-5) mol.L-1, the percent of binding was approximately 95% for the compound tested. When plotting the percent binding (% Cb) against the total concentration (Ctot), a statistically significant difference (p < or = 0.05) was obtained between the slope of the straight line for the (+)-isomer and those for other two compounds.(ABSTRACT TRUNCATED AT 250 WORDS)