Simultaneous determination of the effect of a non-ionic surfactant on the dissolution rate and biological activity of tablets of chlorpromazine hydrochloride

Abstract

The effect of a non-ionic surfactant, polysorbate 80, on the biological activity of chlorpromazine hydrochloride in solution was investigated using the goldfish, Carassius auratus. Below a certain critical concentration the activity was enhanced in unbuffered drug solutions, but above this concentration the activity was diminished, possibly due to some association between surfactant micelles and drug molecules. The rate of solution of chlorpromazine hydrochloride from coated tablets was increased by 2% polysorbate 80, but the activity was decreased when compared with that in a simple aqueous dissolution medium. This is direct evidence of the erroneous conclusions that can be obtained if dissolution measurements alone are used in assessing the effect of additives on drug performance.