Characterization of thymoquinone/hydroxypropyl-ß-cyclodextrin inclusion complex: Application to anti-allergy properties.

Thymoquinone is an effective phytochemical compound in the treatment of various diseases. However, its practical administration has been limited due to poor aqueous solubility and bioavailability. In this work, we developed a novel inclusion complex of thymoquinone and hydroxypropyl-ß-cyclodextrin that features improved solubility and bioactivity. The drug solubility was markedly accelerated in the increasing ratio of hydroxypropyl-ß-cyclodextrin to thymoquinone amount. The formation of the thymoquinone/hydroxypropyl-ß-cyclodextrin inclusion complex was evidenced using X-ray diffraction, differential scanning calorimetry, thermal gravimetric analysis, Fourier transform infrared, scanning electron microscopy and nuclear magnetic resonance. The release behavior of the complex, as well as of their mixtures, was examined in artificial gastric (pH 1.2) and intestinal (pH 6.8) dissolution media. The formulated complex released the drug rapidly at the initial stage, followed by a slow release. Thermodynamic parameters ΔH, ΔS and ΔG were calculated with temperatures ranging from 20 to 45 °C to evaluate the complexation process. The activity of the inclusion complex was evaluated on IgE-mediated allergic response in rat basophilic leukemia (RBL-2H3) cells by monitoring key allergic mediators. The results revealed that compared with free thymoquinone, the inclusion complex more strongly inhibited the release of histamine, tumor necrosis factor-α, and interleukin-4, and was not cytotoxic at the tested thymoquinone concentrations (0.125-4 µg/mL) indicating the inclusion complex possibly had better antiallergic effects. Our finding suggested that the inclusion complex achieved prolonged action and reduced side-effect of thymoquinone.

Synthesis of Radiation Curable Palm Oil-Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations.

Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA) from an epoxidized palm oil product (EPOP) as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated.