Renal ultrastructural alterations induced by various preparations of mefenamic acid

Green electrochemical method for the synthesis of nitro and azo derivatives based on mefenamic acid

Electrochemical study of mefenamic acid (MFA) was carried out with details in water/ethanol mixture by the various voltammetric techniques. The results showed that the oxidation of MFA is highly dependent on pH and follows the Eir mechanism. The EpA1-pH diagram plotted based on the differential pulse voltammograms shows two linear segments, 66 and 26 mV/pH slope. Also, the diffusion coefficient and the surface excess, Ӷ* of MFA in aqueous buffered solution, determined by using the single potential-step chronoamperometry and chronocoulometry methods. Electrochemical nitration of MFA in an aqueous solution and the presence of nitrite ion (1) were both investigated by the cyclic voltammetry and controlled-potential coulometry techniques. Our results indicate that the oxidized form of MFA participates in a Michael-type addition reaction with nitrite ion (1) to form the corresponding Nitromefenamic acids (MFA-4-NO2 and MFA-5-NO2). Also, in another part, a computational study based on the density functional theory (DFT/B3LYP) was performed for the prediction of the best possible pathway in the nucleophilic addition of nitrite ion (1). The electrochemical reduction of produced nitromefenamic acids was investigated using cyclic voltammetry and controlled-potential coulometry techniques. Eventually, two new azo derivatives have been generated via electroreduction of produced nitromefenamic acids and conduction of diazotization reaction, respectively. Both nitro and azo products are approved as paints.

Pharmacokinetics and Metabolism of Liposome-Encapsulated 2,4,6-Trihydroxygeranylacetophenone in Rats Using High-Resolution Orbitrap Liquid Chromatography Mass Spectrometry

2,4,6-trihydroxy-3-geranylacetophenone (tHGA) is a bioactive compound that shows excellent anti-inflammatory properties. However, its pharmacokinetics and metabolism have yet to be evaluated. In this study, a sensitive LC-HRMS method was developed and validated to quantify tHGA in rat plasma. The method showed good linearity (0.5–80 ng/mL). The accuracy and precision were within 10%. Pharmacokinetic investigations were performed on three groups of six rats. The first two groups were given oral administrations of unformulated and liposome-encapsulated tHGA, respectively, while the third group received intraperitoneal administration of liposome-encapsulated tHGA. The maximum concentration (C_max), the time required to reach C_max (t_max), elimination half-life (t_1/2) and area under curve (AUC_0–24) values for intraperitoneal administration were 54.6 ng/mL, 1.5 h, 6.7 h, and 193.9 ng/mL·h, respectively. For the oral administration of unformulated and formulated tHGA, C_max values were 5.4 and 14.5 ng/mL, t_max values were 0.25 h for both, t_1/2 values were 6.9 and 6.6 h, and AUC_0–24 values were 17.6 and 40.7 ng/mL·h, respectively. The liposomal formulation improved the relative oral bioavailability of tHGA from 9.1% to 21.0% which was a 2.3-fold increment. Further, a total of 12 metabolites were detected and structurally characterized. The metabolites were mainly products of oxidation and glucuronide conjugation.