Multiple emulsions have particular properties, such as encapsulation capacity of drugs or cosmetic active, protect the substance encapsulated against oxidation process; ability to serve incompatible substances, for example, hydrophilic characteristics / lipophilic / hydrophilic emulsion for class W/O/W, respectively, in the same system and sustained release of the active or encapsulated drug. Due to the advantages of its structure, the multiple emulsions have attracted great interest in the cosmetics, pharmaceutical, food and chemical industries, but in general its application has limitations regarding the difficulty to elucidate and characterize the parameters involved in the production and stability these systems. Several factors are critical to become a commercially successful multiple emulsion: determine the type and chemical characteristics of the emulsifiers used to characterize the influence of the ratio of the volumes of the oil and water phase in the production and stability of multiple emulsion, to determine the best ratio suitable surfactants between the primary and multiple emulsion, determine the most appropriate method of handling and standardize and validate methods of analysis of multi-system stability. Among these, the most used is the emulsification process in two stages consisting in preparing a primary W/O emulsion and / or O/W which is then re-emulsified (second step) and added to another aqueous phase and / or oily containing hydrophilic or lipophilic surfactants, respectively, forming multiple emulsions of the type W/O/W or O/W/O.
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