A comparative study of surfactant influence on the release of ions from an emulsified ointment base.

An apparatus has been designed and an in vitro method employing radioisotopes has been developed to study medicament release from pharmaceutical semisolids. Radio-labeled mercuric and iodide ions have been incorporated into hydrophilic bases emulsified with 1, 3, and 5 per cent concentrations of anionic, cationic, and nonionic surface active agents and the ability of the bases to release the contained ions has been measured.