Liquisolid Technique: A Novel Approach to Enhance Solubility of Poorly Soluble Drugs

Biovailability of any drug depends on the dissolution of the drug and its release from the dosage form. Solubility is the major challenge for pharmaceutical industries with the development of poorly soluble drugs. There are several approaches for solubility enhancement which includes micronisation, nanonisation, use of salt forms, surfactants, solid dispersions and supercritical fluid recrystallisation, etc. Liquisolid technique is a novel and efficient approach for solubility enhancement. According to this method the conversion of water insoluble drugs into dry looking, non-adherent, free flowing and acceptably compressible powder by incorporating into suitable nonvolatile solvents, carrier and coating materials (It is claimed that if hydrophobic carriers such as Eudragit RL and RS are used instead of hydrophillic carriers in liquisolid system, sustained release systems can be obtained). This free flowing powder is thus subjected to preformulation studies like differential scanning calorimetry, Fourier transformed infrared spectroscopy, angle of slide, flow properties, liquid retention potential, liquid load factor, etc. This powder is subjected to compression for tablet or filled in capsules. This mechanism for solubilty enhancement includes increase in wettability and increase in surface of drug available for dissolution. This method is efficent, economic, viable for industrial production. Due to all this reasons liquisolid technique is most efficient and novel approach for solubility enhancement.