Anti-Candida activity of clotrimazole in combination with dioctyl sodium sulfosuccinate and other surfactants.

Six anionic and five nonionic surfactants were tested for their effect on the fungistatic action of clotrimazole against Candida albicans. All of the anionic agents that did not contain an ethylene oxide group were capable of potentiating the anti-Candida activity of clotrimazole, whereas all five members of the polyoxyethylene surfactant group, including four nonionic agents and one anionic agent, acted in an antagonistic fashion. The combination of clotrimazole and the anionic surfactant dioctyl sodium sulfosuccinate was the most potent in synergy and, thus, more precise studies were made with this combination. Although appropriate combinations of the two drugs showed a potent fungicidal activity against proliferating cultures, none of these combinations tested was lethal when cell growth was restricted by nutritional deficiency. The lethal effect of the combined drugs was partly reversed when growing cultures were treated in the presence of an osmotic stabilizer. Whether cells were treated with moderate and higher concentrations of clotrimazole and dioctyl sodium sulfosuccinate, alone or in combination, there was little change in cell wall content of total protein, carbohydrate, or lipid from that in untreated control cells. However, there was a significant decrease in the cell wall content of phospholipid when moderate concentrations of the two drugs were combined.