Abstract

MISCIBILITY AND THERMAL PROPERTIES OF POLY (VINYLPYRROLIDONE-VINYL ACETATE)/ EFAVIRENZ GLASS BLENDS PREPARED BY MELT PROCESSING

Lucyenne Barbosa*, Marcos L.Dias, Fabio Dantas, Rodrigo Anjos, Jonatas Vieira, Rafael Seiceira

Abstract

Efavirenz (EFV) is HIV crystalline drug with poor water-solubility exhibiting low dissolution rate andlimited oral bioavailability. In this work, amorphous solid solutions of a vinylpyrrolidone-vinyl acetatecopolymer (Kollidon VA64) with EFV containing up to 50 wt% of the drug were prepared using melt processing in a mixing chamber. Melt processing studies revealed that a decrease in torque and specific processing energy was observed as the drug concentration increased. Attenuated total reflectance infrared spectroscopy (ATR), X-ray powder diffraction (XRD) and thermal analysis were used to examine the morphology, thermal behavior and chemical stability of the glass solids. Kollidon VA64/EFV blends showed miscibility in concentrations up to 50 wt% of EFV. Following storage for one year at 25ºC the Kollidon/EFV glass solid remained completely amorphous.

Keywords: Efavirenz, polyvinylpyrrolidone, mixing chamber, amorphous solid solution.