Water Content Of Microemulsion Research Articles

Adapalene Microemulsion for Transfollicular Drug Delivery

The aim of this study was to develop a microemulsion formulation of adapalene for transfollicular delivery. A pseudoternary phase diagram was developed for microemulsion consisting of oleic acid as oil phase, tween 20 as surfactant, Transcutol® as cosurfactant, and deionized water. Differential tape stripping and confocal laser scanning microscopy were performed to determine the penetration of microemulsion through hair follicles. Transmission electron microscopy, dynamic light scattering, polarizing light microscopy, and differential scanning calorimetry were performed to characterize the microstructures of microemulsion. The pH and viscosity of the microemulsions were also determined. Permeation studies were carried out in vitro on porcine ear skin over a period of 24 h using Franz diffusion cells. The drug penetration in the hair follicles increased from 0.109 ± 0.03 to 0.292 ± 0.094 μg, as the microstructure of microemulsion shifted from oil-in-water to bi-continuous, with increase in water content of microemulsion. Confocal laser scanning microscopy images suggested that hair follicles provided the path for transfollicular permeation of adapalene microemulsion. These results suggest that microemulsion penetrated through hair follicles and are promising for transfollicular drug delivery.

Extraction of rare earth metal samarium by microemulsion

The influence of the concentration of sodium oleate (NaOL), alcohol and the nature of the internal water phase on the water content of microemulsion was studied. The effect of the concentration of NaOL, sodium stearate, alcohol, salting-out agent, Alamine 336 added and of the contact time, volume ratio of the aqueous to microemulsion (R) and temperature on the extraction yield of samarium was investigated. The result shows that the extraction of samarium is effective under well-defined conditions utilizing WinsorII microemulsion systems.

Study on the Structure Transition of CTAB/1-Butanol/Heptane/Water Microemulsions by Pt Ultramicroelectrode

Summary Ultramicroelectrode voltammetric measurements have been used in the microemulsions of CTAB/1-butanol/heptane/water to calculate the diffusion coefficient which can reflect the structure transition of the microemulsions. It is found that with increasing water content of microemulsions, the apparent diffusion coefficient (D app) of the probe decreases monotonically with three transition points. The first two transition points indicate the change in the structure of microemulsions, that is from water in oil region to bicontinuous phase and then to oil in water region, while the third one differs from previous reports. The time resolved fluorescence quenching (TRFQ) technique has been carried out to obtain the aggregation number of the microemulsions in order to analyze the abnormal transition point. According to the TRFQ experiment, we find that the aggregation number of the microemulsion decrease with water content increasing between 50%–60%, and then tend to identical. These results suggest that the last transition point of the diffusion coefficient is because of the forces between oil droplets. The self-diffusion coefficient of oil droplet in the o/w region is calculated simultaneously. Based on these experimental results, we analyze the composition of the interface between oil and water.