Electrochemical Oxidation of Pentoxifylline and its Analysis in Pure and Pharmaceutical Formulations at a Glassy Carbon Electrode

Molecular Interaction of Hemorrheologic Agent, Pentoxifylline with Bovine Serum Albumin: An Approach to Investigate the Drug Protein Interaction Using multispectroscopic, Voltammetry and Molecular Modelling Techniques

The interaction between pentoxifylline (PTX) and bovine serum albumin (BSA) was studied under physiological condition by spectroscopic, voltammetry and molecular modelling techniques. The results of fluorescence studies revealed that the quenching mechanism of BSA by PTX was a static procedure. Binding constant of PTX-BSA was calculated and its value found to be 8.895 × 104 M−1, which is in close agreement with the results obtained from UV-Visible and voltammetry approach. The negative values of thermodynamic parameters (ΔG, ΔH and ΔS) indicated that van der Waals force and hydrogen bonding play major roles in the interaction of PTX with BSA. Based on Forster’s theory of non-radiation energy transfer, the binding distance (r) between the donor (BSA) and acceptor (PTX) was found to be 5.38 nm (298 K). The results of UV-Visible and circular dichroism (CD) spectroscopy showed that PTX interacts with BSA and induces conformational changes by reducing the α-helix content. The results of the UV-visible and voltammetry studies were further verified by the molecular docking method. Molecular modelling studies revealed possible residues involved in the drug-protein interaction and indicated that PTX binds to Site IIA of BSA.

Degradation kinetics and mechanism of pentoxifylline by ultraviolet activated peroxydisulfate

Degradation of pentoxifylline (PTX) by sodium peroxydisulfate (SPDS) assisted by UV irradiation has been investigated in deionized water. The treatment was more favorable over direct photolysis or peroxydisulfate oxidation alone. The effects of various parameters, including different dosage of oxidant agent, PTX concentration, initial solution pH levels, and the presence of inorganic ions like chloride, nitrate and carbonate have been evaluated. The rate of PTX decomposition depends on the oxidant agent dose. The highest degradation was determined at pH 10.5, which can be explained by the generation of additional hydroxyl radicals (HO˙) in the reaction between sulfate radicals and hydroxide ions. The presence of inorganic ions, especially the carbonate ions quench valuable sulfate radicals and have successfully retarded the PTX decomposition. Six PTX oxidation products were identified using UPLC-QTOF-MS for trials in a basic environment. The main degradation product (3,7-dimethyl-6-(5-oxohexyloxy)-3,7-dihydro-2H-purin-2-one) was isolated by column chromatography and identified by ¹HNMR and LC MS analyzes.

Degradation of pentoxifylline (PTX) by sodium peroxydisulfate (SPDS) assisted by UV irradiation has been investigated in deionized water.