Microemulsion & sub-micron emulsion process & compositions

An oil in water microemulsion or sub-micron emulsion composition for dermal delivery of at least one pharmaceutically active ingredient, the composition comprising:

• at least one pharmaceutically active ingredient;
• an oil in water microemulsion or sub-micron emulsion comprising an oil phase dispersed throughout a water phase, said oil phase comprising at least one selected from the group consisting of an animal oil, a mineral oil, a vegetable oil, a silane, a siloxane, an ester, a fatty acid, a fat, a halogen compound, and an alkoxylated alcohol, and at least one lipophilic surfactant, said water phase comprising at least one hydrophilic surfactant and water;
• and
• a non-surfactant amphiphilic compound that is added to the composition after formation of said microemulsion or sub-micron emulsion and is miscible in said water phase,
• wherein said pharmaceutically active ingredient is in said water phase or is in both said oil phase and said water phase, and the weight ratio of said at least one hydrophilic surfactant to said at least one lipophilic surfactant is approximately 9.0:1.0 to 2.0:3.0.

A method of medical or cosmetic treatment of a dermal condition comprising:

• applying to the skin of a patient requiring such treatment an effective amount of oil in water (O/W) microemulsion or sub-micron emulsion composition comprising:
• at least one pharmaceutically active ingredient;
• an oil in water microemulsion or sub-micron emulsion comprising an oil phase dispersed throughout a water phase, said oil phase comprising at least one selected from the group consisting of an animal oil, a mineral oil, a vegetable oil, a silane, a siloxane, an ester, a fatty acid, a fat, a halogen compound, and an alkoxylated alcohol, and at least one lipophilic surfactant, said water phase comprising at least one hydrophilic surfactant and water;
• and
• a non-surfactant amphiphilic compound that is added to said composition after formation of said microemulsion or sub-micron emulsion and is miscible in said water phase,
• wherein said pharmaceutically active ingredient is in said water phase or is in both said oil phase and said water phase, and the weight ratio of said at least one hydrophilic surfactant to said at least one lipophilic surfactant is approximately 9.0:1.0 to 2.0:3.0.