Preparation and physicochemical characterization of a solid dispersion of (3, 5, 6-trimethylpyrazin-2-yl) methyl 3-methoxy-4-[(3, 5, 6-trimethylpyrazin-2-yl) methoxy] benzoate (VA-T) and polyvinylpyrrolidone

Abstract

Ischemic brain injury is a major disease which threatens human health and safety. (3, 5, 6-trimethylpyrazin-2-yl) methyl 3-methoxy-4-[(3, 5, 6-trimethylpyrazin-2-yl) methoxy] benzoate (VA-T), a newly discovered lead compound, is effective for the treatment of ischemic brain injury and its sequelae. But the poor solubility of VA-T leads to poor dissolution and limited clinical application. In order to improve the dissolution of VA-T, the pharmaceutical technology of solid dispersions was used in the present study. VA-T/polyvinylpyrrolidone (PVP) solid dispersion was prepared by the solvent method. The dissolution studies were carried out and solid state characterization was evaluated by differential scanning calorimetry (DSC), infrared spectroscopy (IR), x-ray diffraction (XRD) and scanning electron microscopy (SEM). The dissolution rate of VA-T was significantly improved by solid dispersion compared to that of the pure drug and physical mixture. The results of DSC and XRD indicated that the VA-T solid dispersion was amorphous. The IR spectra showed the possible interaction between VA-T and PVP was the formulation of hydrogen bonding. The SEM analysis demonstrated that there was no VA-T crystal observed in the solid dispersions. The ideal drug-to-PVP ratio was 1:5. In conclusion, the solid dispersion technique can be successfully used for the improvement of the dissolution profile of VA-T.

Keywords: Dissolution; Ischemic stroke; Physicochemical characterization; Solid dispersions; VA-T.