Development and characterization of taste masked Efavirenz pellets utilizing hot melt extrusion

The objective of this study was to formulate taste-masked pellets of Efavirenz (EFZ) with Eudragit E PO as the matrix polymer utilizing hot melt extrusion (HME) technology. The drug/polymer physical mixtures were extruded as rods with a co-rotating twin-screw extruder and then pelletized. The chemical interaction between EFZ and Eudragit E PO was determined using Fourier transform infrared (FTIR) spectroscopy. Solid-state characterization of EFZ in the Eudragit E PO matrix was carried out using differential scanning calorimetry (DSC), Powder X-ray Diffraction (PXRD) and Scanning electron microscopy (SEM) techniques. The solubility of EFZ was improved significantly due to its conversion into a more water-soluble amorphous form. Drug load had a significant effect on EFZ release characteristics from the pellets. In vitro release profiles obtained with the extruded pellets at pH 6.8 (simulated salivary medium) indicated that EFZ release would be extremely limited in the saliva, unlike the physical mixture, thus avoiding irritation of the oral mucosa (BMS, burning mouth syndrome). More than 90% drug release in 30minutes was observed in simulated gastric medium (pH 1.2) with the extruded pellets. The dissolution rate of EFZ from the melt extruded pellets was faster than that from thephysical mixtures at all drug loads (p < 0.05) in simulated gastric medium. Taste masked EFZ pellets were thus successfully developed without affecting the dissolution rate in simulated gastric medium.