The emulsifying effectsoftwelve anionic and five cationic surfactants on the nonaqueous immiscible system, glycerin and olive oil, were studied. Three anionic agents, dioctyl sodium sulfosuccinate, diamyl sodium sulfosuccinate, and calcium stearate, and two cationic agents, benzalkonium chloride and lauryltrimethylammonium bromide, failed to stabilize the system. On the other hand, four anionic agents, tetrasodium-N-(1,2-dicarboxyethyl)-N-octadecyl-sulfosuccinamate, sodium lauryl ether sulfate, sodium lauryl sulfate, and sodium stearate, and three cationic agents, stearyltrimethylammonium chloride, cetyl yridinium chloride, and stearyldimethylbenzylammonium c h l o r i d e , r d u c e d stalle emulsions. The anionic agents formed by the saponification of e fatty acids present in the olive oil with 2-amino-2-methyl-1,3-propanediol, uis (hydroxymethyl) aminomethane, uiethanolamine, ethanolamine, or ammonia, yielded clear, stable emulsions. Emulsification occurred more readily, or preferentially, when the surfactant was first added to the glycerin. All of the emulsions formed were of the oil-in-glycerin type, except those containing sodium stearate or stearyltrimethylammonium chloride.
URING RECENT YEARS rapid advances have been made in the technology of surfaceactive agents (surfactants). A multitude of new agents have been developed and their properties and actions studied. These studies have resulted not only in a vast expansion of the knowledge of the better known actions, but also in the discovery of new actions and new applications for these agents. Surfactants exhibit many properties, among which are included emulsifying, demulsifying, wetting, foaming, antifoaming, dispersing, solubilizing, detergent, and spreading actions. Many of these actions are interrelated and all are manifestations of the thermodynamic function of surfactants in effecting a reduction in the surface or interfacial tension between a liquid and an adjoining phase. The amphiphilic nature of surfactant molecules results in a simultaneous attraction for both polar and nonpolar substances which accounts for some of their actions.
The actions enumerated above find applications in a large number of industries, including the pharmaceutical and cosmetic industries. Many pharmaceutical applications have been extensively investigated. For example, the use of surfactants as emulsifying agents for oil-water systems, as detergents, dispersing agents, suppository bases, disinfectants, preservatives, and fecal softeners, is well established. There are also reports in the literature regarding the use of surfactants as solubilizing agents for volatile oils (1), phenobarbital in a nonalcoholic vehicle (2),