Microsphere formulations have an advantage over the conventional tablet or capsule formulations since it increases the surface area exposed to the absorption site and thus increasing the absorption of the drug and decreasing the dosing frequency of the drug.
Microemulsions are clear, thermodynamically stable isotropic liquid mixtures of oil, water and surfactant, frequently in combination with a cosurfactant. The aqueous phase may contain salt(s) and/or other ingredients, and the “oil” may actually be a complex mixture of different hydrocarbons.
Emulgel is one of the recent technology in NDDS used topically having characteristics of dual control release i.e. emulsion as well as gel. When gel and emulsion are used in combined form, the dosage form is referred as Emulgel.