Determination of ibuprofen and novocaine hydrochloride with the use of water–micellar solutions of surfactants Original Research Article

The solubility and acid–base properties of ibuprofen in water–micellar media of surfactants were studied. A new visual method for the titrimetric determination of ibuprofen in pure form was proposed. The smallest pK value (4.43) and the greatest solubility (8.1 mg ml−1) of ibuprofen were achieved using an aqueous cationic micellar medium of 0.1 M tridecylpyridinium bromide. The titration was performed with 0.05 M potassium hydroxide aqueous solution and the exact end-point was determined with the use of xylenol blue as indicator. Conditions for the individual determination of ibuprofen and novocaine hydrochloride in their 1:1 mixtures with the use of 0.1 M tridecylpyridinium bromide were proposed.