Microemulsions in the Systems with Lecithin and Oils from Tropical Plants for Drug Delivery †.

It was shown that to obtain reverse microemulsions in lecithin–oleic acid–vaseline oil–vegetable oil–essential oil–water systems, oil from the tropical plant gac (Momordica cochinchinensis) and turmeric essential oil (Curcuma longa) can be used. At least 6.5 wt.% of water can be introduced into the microemulsion at a lecithin concentration of 20 wt.% in the organic phase, with a vaseline oil and gac oil ratio of 1:1 by weight, and an oleic acid and lecithin molar ratio 0.2–0.8. The hydrodynamic diameter of the microemulsion droplets, depending on the content of water and lecithin, was from 3 to 21 nm. Using the dialysis method on the model of the water-soluble dye Rhodamine C, it was shown that the rate of its transfer from the microemulsion to the physiological solution was 15.4 × 10⁻³ g/(m²∙h); approximately 3.2% of the dye was released in 6 h, which allows for the development of drugs with a sustained release of medicinal substances. [ABSTRACT FROM AUTHOR]