Development of curcumin-loaded composite phospholipid ethosomes for enhanced skin permeability and vesicle stability.

Ethosomes are widely applied as the carriers for the transdermal delivery of hydrophobic and hydrophilic drugs. Herein, curcumin-loaded ethosomes (CE) with different phospholipid composition were formulated and thoroughly compared. A significant interaction between the unsaturated phosphatidylcholine (PC) and saturated hydrogenated phosphatidylcholine (HPC) was found by molecular simulation and differential scanning calorimetry (DSC), which led to the reduction of PC peroxidation with the presence of HPC. Subsequently, the composite phospholipid ethosomes containing curcumin were prepared for the first time to evaluate their properties in comparison with the conventional ethosomes composed of PC (CE-P) or HPC (CE-H). CE with PC/HPC ratio of 1:1 (CE-P1H1) with the best vesicle stability and flexibility significantly decreased the uptake by HaCaT cells compared to CE-H and free curcumin, indicating reduced skin cell toxicity. Compared with free curcumin, CE-P1H1 had the highest transdermal efficiency (p < 0.001), followed by CE-P (p < 0.05), partly due to the fact that CE-P1H1 could disturb lipid domain of stratum corneum (SC). Moreover, CE-P1H1 was found to promote curcumin for deep penetration of the skin via the hair follicles route. Our study has shown that using composite phospholipid ethosomes as lipid vesicular carriers could enhance transdermal penetration of drugs and increase in the vesicle stability.

[Comparative study of penetration-enhancing effect in vitro of cinnamon oil and cinnamaldehyde on ibuprofen].

To compare the penetration-enhancing effect of cinnamon oil and its main components (cinnamaldehyde) on ibuprofen and their self-percutaneous absorption behavior in vitro. Firstly, cinnamon oil was extracted by steam distillation, then the compositions were analyzed by gas chromatography mass spectrometry (GC-MS) and the cinnamaldehyde content in cinnamon oil was determined by high performance liquid chromatography (HPLC). With azone as positive control, ibuprofen as model drug, cinnamon oil and cinnamaldehyde as penetration enhancers (PE) were prepared and administered to the SD rat's abdominal skin. The penetration-enhancing effects of cinnamon oil and cinnamaldehyde and their own transdermal absorption properties were compared. The results showed that yield of cinnamon oil was (3.55±0.36)% (n=3), and the cinnamaldehyde content in cinnamon oil was (73.48±0.21)% (n=3). As compared with blank group, the enhancing rate (ER) of cinnamon oil, cinnamaldehyde, and azone was 3.56, 1.13, 2.47 respectively. The cumulative penetration rate of cinnamaldehyde in cinnamon oil and cinnamaldehyde monomer in 24 h was (63.30±0.98)%, (51.03±3.34)% (n=4) respectively. The penetration-enhancing effect of cinnamon oil was significantly better than that of cinnamaldehyde, indicating the existence of muti-component synergy. The penetration rate of cinnamaldehyde in cinnamon oil was higher than that of cinnamaldehyde monomer, suggesting that a "pull effect" may be present.