Liquisolid technique: An approach to enhance the dissolution rate of olanzapine

Abstract

The present work was aimed at enhancing the dissolution rate of olanzapine, an antipsychotic agent using the liquisolid technique. Liquisolid system is an innovative technique used for enhancing dissolution rate and bioavailability of poorly soluble drugs. A mathematical model was utilized to formulate liquisolid tablets. Two non-volatile liquids were used in the design of liquisolid tablets, Tween 80 and propylene glycol. The effect of formulation parameters, such as drug:non-volatile liquid ratio and carrier:coating ratio was observed. Microcrystalline cellulose and silica were used as carrier and coating materials, respectively. All liquisolid formulations showed higher drug dissolution rate than directly compressible tablets and marketed tablets. Differential scanning calorimetry revealed that the drug has got solubilised in the liquid vehicle, which was further supported by x-ray diffraction studies and scanning electron microscopy. Infrared spectroscopy studies indicated the absence of incompatibility between drug and non-volatile solvents. This study shows that liquisolid technique is a promising alternative for improvement of dissolution rate of water-insoluble drug.