ENHANCEMENT OF WATER SOLUBILITY OF POORLY WATER SOLUBLE DRUGS: A REVIEW
Renu Tiruwa*, Ashutosh Badola,
The solubility of a substance (solute) is the maximum quantity of solute that can dissolve in a certain quantity of solvent at a specified temperature and pressure. In the other words the solubility can be define as the ability of one substance to form a solution with another substance in which one is solute and another is solvent. The substance to be dissolved is called as solute and the dissolving fluid in which the solute dissolve is called as solvent, which together form a solution. Solubility, dissolution of solute in solvent to give a homogenous system, is important parameters to achieve desired concentration of drug in systemic circulation for pharmacological response. Today Poorly soluble drugs are problem in pharmaceutical formulations, poor solubility, making them poor candidates as new drugs. And about 40% drugs from newly developed chemical entities are lipophilic in nature and fail to reach market due to poor water solubility. The poor solubility of drugs remains one of the most challenging aspects in formulation development. We can overcome from this problem by combinatorial chemistry and various methods to improve the dissolution of poorly soluble drugs. It needs to improve the solubility and dissolution rate for poorly soluble drugs because these drugs possess low absorption and bioavailability. Any drug to be absorbed must be present in an aqueous solution at the site of absorption. The oral route of administration is the most preferred and widely acceptable due to ease of ingestion for many drugs. Drugs with slow dissolution rate show the incomplete absorption leading to low bioavailability by oral administration. Various techniques are used for the improvement of the solubility of poorly water soluble drugs.
[Full Text Article]