abstract |
An oil-in-water microemulsion or sub-micron emulsion composition for dermal delivery of at least one pharmaceutically active ingredient, comprising: a first part including at least one occlusive agent and one or more lipophilic surfactants dispersed throughout a second part including water and at least one hydrophilic surfactant, and a non-surfactant amphiphilic type compound, pharmaceutically active ingredient, and water. It has been found that if a non-surfactant amphiphilic type compound is added together with the second part as would conventionally be the case, a microemulsion or sub-micron emulsion is not formed, by adding the so called third part, phase assembly occurs at a lower temperature than would be expected and moreover, this phase appears to assist in maintaining the microemulsion or sub-micron emulsion characteristics of the formulation during storage at normal temperatures. |