Degradation of Ampicillin and Flucloxacillin Antibiotics via Oxidation by Alkaline Hexacyanoferrate(III): Kinetics and Mechanistic Aspects

Effective Treatment Methodology for Environmental Safeguard Catalytic Degradation of Fluconazole by Permanganate Ions in Different Acidic Environments: Kinetics, Mechanistics, RSM, and DFT Modeling

In this paper, the degradation of fluconazole drug (Flz) was explored kinetically utilizing permanganate ion [MnO4-] as an oxidant in different acidic environments, namely sulfuric and perchloric acids at various temperatures. Stoichiometry of the reactions between Flz and [MnO4-] in both acidic environments was attained to be 1.2 ± 0.07 mol. The kinetics of the degradation reactions in both cases were the same, being unit order regarding [MnO4-], fewer than unit orders in [Flz], and fractional second orders in acid concentrations. The rate of oxidative degradation of fluconazole in H2SO4 was higher than that in HClO4 at the same investigational circumstances. The addition of small amounts of Mg2+ and Zn2+ enhanced the degradation rates. The activation quantities were evaluated and debated. The gained oxidation products were characterized using spot tests. A mechanistic approach for the fluconazole degradation was suggested. Finally, the rate law expressions were derived which were agreed with the acquired outcomes. The rates of degradation for various [Flz] were mathematically modeled using the response surface methodology (RSM). The RSM model's conclusions and the experimental findings are in agreement. The oxidative degradation mechanism of Flz using density functional theory (DFT) was performed. The fluconazole drug degrades in acidic settings, protecting both the environment and human health, according to a method that is easy to use, powerful, inexpensive, practical, affordable, and safe.

Dosing Considerations for Combination Antistaphylococcal β-Lactam and Glyco/lipopeptide Salvage Therapy for Resistant Gram-Positive Infections: A Systematic Review

OBJECTIVE

The objective of this systematic review is to evaluate dosing regimens of combination salvage regimens used as part of infectious disease pharmacotherapy.

DATA SOURCES

A systematic review was conducted on PubMed, MEDLINE, Scopus, ProQuest Central, and CINAHL through March 2021 using the following terminology: "combination" OR "Seesaw" OR "see-saw" OR "salvage" AND "infection" OR "resistant infection" OR "Gram-positive" AND "beta-lactam" OR "cephalosporin" OR "carbapenem" OR "monobactam" OR "glycopeptide" OR "lipopeptide."

STUDY SELECTION AND DATA EXTRACTION

Following the application of inclusion and exclusion criteria, 8 pieces of literature were ultimately included in this review.

DATA SYNTHESIS

Vancomycin in combination with another agent was most commonly prescribed as initial or empirical therapy. The most common combination salvage therapy regimen consisted of daptomycin in doses up to 12 mg/kg IV every 24 hours with ceftaroline 200 to 600 mg IV every 8 to 12 hours. Although the duration of combination salvage therapy varied drastically, blood culture clearance was typically observed within 24 hours.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Antimicrobial-resistant Gram-positive organisms have posed an emergent threat to antimicrobial stewardship initiatives. Utilizing either a glycopeptide or lipopeptide antibiotic in combination with an antistaphylococcal β-lactam antibiotic has demonstrated efficacy in treating resistant bacteria. This work describes the heterogeneity of dosing regimens and seeks to define an optimal dose, duration, and combination of antibiotics.

CONCLUSIONS

Combination salvage therapy has demonstrated efficacy and safety in treatment of resistant Gram-positive infections. It appears the combination of daptomycin and ceftaroline can clear resistant infections expeditiously.

Unprecedented Treatment Strategy of Aquatic Environments: Oxidative Degradation of Penicillin G by Chromium Trioxide in Acidic Media and the Impact of Metal Ion Catalysts: Kinetics and Mechanistic Insights

Degradation kinetics and pathways of the antibiotic penicillin G (Pen) have been examined via oxidation by chromium trioxide (CrVI) in aqueous sulfuric and perchloric acid media. The oxidation reactions were monitored by spectrophotometry at 298 K. In both acidic media, penicillin G oxidation was set to proceed through acid catalysis. The stoichiometry of the reactions designated that 3 moles of Pen required 2 moles of CrVI. The kinetics of Pen oxidation in both acids was of the first order with regard to [CrVI] and less-than unity order with regard to [Pen] and [H+] in their variation. The rates of reactions displayed negligible impacts upon altering ionic strengths or dielectric constants of the reaction media. There was no intrusion of free radicals throughout the redox reactions. Addition of low concentrations of Ni2+, Cu2+, and Zn2+ ions enhanced the oxidation rates, while addition of Cr3+ as a described product did not noteworthily alter the rates. Under comparable investigational circumstances, the oxidation rates in HClO4 were almost 2-fold greater than in H2SO4. The oxidation products of penicillin G were identified by spectral analysis and spot tests as phenyl acetic acid, 2-formyl-5,5-dimethyl-thiazolidine-4-carboxlate ion, ammonium ion, and carbon dioxide. Reliance of reaction rates on temperature has been explored, and the activation and thermodynamic parameters were estimated and debated. In view of the noted reactions' orders and products' identification, a plausible mechanism for the oxidation reactions was suggested. The derived rate law was set to be in accordance with the acquired results. This study offers an unprecedented simple and low-cost treatment method for removal or degradation of certain pollutants for protecting the environment and human health.