“…Figure 1 also shows the comparison of negatively (LPKO) and positively charged vesicles (LPKO-SA). SC contains a high amount of negatively charged lipids, thus by having the same charge as the skin, negatively charged vesicle can increase the possibility of drug absorption or penetration into the skin (Sinico et al, 2005;Yoo et al, 2008). However, depending on drug type, negatively or positively charged vesicles were able to increase the accumulation or penetration of the drug (Katahira et al, 1999;Ogiso et al, 2001;Sinico et al, 2005;Song and Kim, 2006).…”