Development of self-microemulsifying systems for Thai herbal extract

Abstract

Keywords: Areca catechu L.; Curcuma longa L.; Garcinia mangostana L.; Oryza sativa L.; Pseudoternary phase diagrams; Self-microemulsifying systems

Objectives: This work aimed to prepare the pseudoternary phase diagrams of self-microemulsifying systems for Thai herbal extract.

Methods: Thai herbal extract recipe, namely “Ya-Sa-Marn-Phlae”, has been widely used for the treatment of wounds and skin infections. The Thai herbal extract was prepared by Dr.Chonlatid Sontimuang, Faculty of Traditional Thai Medicine, Prince of Songkla University. The pseudoternary phase diagrams of self-microemulsifying systems were prepared from caprylic acid, each Tween^® 20 or mixture of Tween^® 80 and absolute ethanol (8:2), and propylene glycol as oil phase, surfactant phase, and co-surfactant phase, respectively. The 1% w/w Thai herbal extract was mixed in self-microemulsifying systems. The appearance of self-microemulsifying systems was observed by visual observation and graded in 4 levels. Then, they were diluted with distilled water and analysed the particle size, size distribution, and zeta potential.

Results: The pseudoternary phase diagrams showed the 4 levels for self-microemulsifying systems which had the particle size in ranged of 36 – 182 nm with low polydispersity index. When the Thai herbal extract was loaded, the size of particle was less than their blank self-microemulsifying systems. In addition, the zeta potential of all self-microemulsifying systems showed between -8.22 to -2.22 mV.

Conclusion: This work could prepare the self-microemulsifying systems for Thai herbal extract recipe, namely “Ya-Sa-Marn-Phlae” that might be developed for the herbal cosmetic products.