The Liquisolid Technique for Enhancement of Drug Dissolution

Liquisolid technique is based upon the admixture of drug loaded solutions with appropriate carrier and coating materials. The use of non-volatile solvent causes improved wettability and ensures molecular dispersion of drug in the formulation and leads to enhance solubility. By using hydrophobic carriers (non-volatile solvents) one can modify release (sustained release) of drugs by this technique. Liquisolid compacts demonstrated a considerably higher drug dissolution rates than those of conventionally made capsules and directly compressed tablets. This was due to the increased wetting properties and surface of drug available for dissolution. Liquisolid technique is a new and promising method that can enhance the dissolution rate of drugs. This review paper highlights the advantages, disadvantages, mechanism of enhanced drug release, classification, evaluation and application of liquisolid technique to enhance the solubility and dissolution of water insoluble drugs. Liquisolid system is characterized by flow behavior, wettability, powder bed hydrophilicity, saturation solubility, drug content, differential scanning calorimetry, Fourier transform infra red spectroscopy, powder X-ray diffraction, scanning electron microscopy, in-vitro release and in-vivo evaluation. By using this technique, solubility and dissolution rate can be improved, sustained drug delivery systems be developed for the water soluble drugs.