The study was conducted to enhance the dissolution rate of ketoconazole (KCZ) (a poorly water-soluble drug) using the liquisolid technique. Microcrystalline cellulose, colloidal silica, PEG400 and polyvinyl pyrrolidone (PVP) were employed as a carrier, coating substance, nonvolatile solvent and additive in the KCZ liquisolid compact formulation, respectively. The drug-to-PEG400 and carrier-to-coating ratio variations, PVP concentration and aging effects on the in vitro release behavior were assessed. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) data revealed no alterations in the crystalline form of the drug and the KCZ-excipient interactions within the process. The load factor and the drug release rate were significantly enhanced compared to directly compressed tablets in the presence of the additive. Increasing the PEG400-to-drug ratio in liquid medications enhanced the dissolution rate remarkably. The dissolution profile and hardness of liquisolid compacts were not significantly altered by keeping the tablets at 40 °C and relative humidity of 75 % for 6 months. With the proposed modification of the liquisolid process, it is possible to obtain flowable, compactible liquisolid powders of high-dose poorly-water soluble drugs with an enhanced dissolution rate.
Keywords: Avicel; dissolution rate; ketoconazole; liquisolid; polymorphic changes.