EMULGEL FORMULATION AND IN VITRO AND IN VIVO ASSESSMENT 13 CONCLUSION According to the obtained results in this study, it could be concluded that the natural emulgel, including virgin olive and LG essential oils extracted from the Holy Land, was successfully formulated based on its in vitro assessment. Besides, this product showed a Figure 5. Skin deformation curve obtained with CutoMPA 580, aperture 2 mm. Figure 6. Maximal recovery area of the skin.

JOURNAL OF COSMETIC SCIENCE 14 deal in vivo quality. It showed a signifi cantly higher sensorial effect on human skin than the same emulgel without LG. However, further investigations should be considered for enhancing the shelf stability of the formulation. Moreover, the application of LG emulgel on human skin provides a moderate sunscreen effect, which may be benefi cial during the daily exposure to sunlight. ACKNOWLEDGMENTS Many thanks for the assistance of the technicians Mohamad Arar and Linda Esa. We also would like to thank Mr. Jonathan E. Wright from the language center, An-Najah National University, for English language editing of this manuscript. REFERENCES (1) T. Igarashi, K. Nishino, and S. K. Nayar, The appearance of human skin: a survey, Found. Trends® Com- put. Graph. Vis., 3(1), 1–95 (2007). (2) E. Xhaufl aire-Uhoda, E. Maca r enko, R. Denooz, C. Charlier, and G. E. Piérard, Skin protection creams in medical settings: successful or evil, J. Occup. Med. Toxicol, 3, 15 (2008). (3) A. Alexander, A. Khichariya, S . Gupta, R. J. Patel, T. K. Giri, and D. K. Tripathi, Recent expansions in an emergent novel drug delivery technology: emulgel, J. Controlled Release, 171 (2), 122–132 (2013). Figure 7. Relative contributions of the visc oelastic plus viscous and the elastic distension to the total deformation.