STUDY THE EFFECT OF CO SOLVENT ON THE SOLUBILITY OF A SLIGHTLY WATER SOLUBLE DRUG

The solubility of a drug depends upon the solvent. Hydrophilic drug are soluble in hydrophilic solvent while hydrophobic drugs are soluble in hydrophobic solvent, sometimes drugs contain both hydrophilic and hydrophobic part and single solvent that in sufficient to improve the solubility of drug is required.  Frequently a soluble is more soluble in a mixture of solvents that in a single solvent alone, this phenomenon is known as co solvency and the solvent in combination increase the solubility of the solute is called the co solvents. The aim of present study was to study the effect of co solvents on the solubility of benzoic acid. From the graph it has been seen that the solubility of benzoic acid increases with the increased of concentration of co-solvent. When the straight line was extrapolated to Y axis, the intercept gives the solubility of benzoic acid in water. Key words:  Solubility, poorly soluble drugs, benzoic acid, IPA, co solvents