Introduction:

emulsions are a type of pharmaceutical preparation widely used in topical applications consisting of two-phase systems of oil-in-water or water-in-oil, where the desired active ingredient is incorporated into one of the phases depending on its solubility. Several studies show that stability is greater in emulsions with liquid-crystalline structures. The liposoluble active substance Miconazole, which acts as an antifungal agent, is solubilized in the oil phase of the emulsion as well as in the fraction of the hydrocarbon chain in liquid crystals.

Method:

microscopic techniques were used to analyze the characteristics of both a conventional emulsion and another one containing the liquid crystals. Miconazole was incorporated into both emulsions; drop dimensions in the internal phase were determined and the liquid crystals were characterized by polarization microscopy.

Results:

through the analysis of the microscopic images of the formulation with liquid crystals with Miconazole and without Miconazole, it was possible to determine that approximately 80% of the drops have dimensions ranging from 0.5µm - 1µm. Microscopic observations with polarized light allowed us to determine that liquid crystals have birefringence with the formation of negative uniaxial extinction crosses, which are characteristic of laminar lyotropic phases with focal conical textures.

Conclusions:

the results show that the addition of Miconazole does not interfere with the formation of the structure of the liquid crystals. Therefore, the formation of liquid crystals depends both on the components of the formulation and the preparation technique.

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