Mechanism of transdermal permeation promotion of lipophilic drugs by ethosomes

Abstract

Ethosomes can promote the penetration of lipophilic drugs into the skin, but the underlying mechanism is still unknown. The purpose of this study was to investigate the mechanism of transdermal permeation promotion of lipophilic drugs by ethosomes. The formulation of ethosomes was optimized using the Box–Behnken experimental design, in which Rhodamine B and 1-palmitoyl-2-{12-[(7-nitro-2-1,3-benzoxadiazol-4-yl)amino]dodecanoyl}- sn -glycero-3-phosphocholine were used to simulate a model lipophilic drug and act as a fluorescent tracer of ethosomal phospholipids, respectively. Liposomes with the same phospholipid concentration and a hydroethanolic solution with the same ethanol concentration were also prepared as controls. The percutaneous progression of the above fluorescent preparations was observed by confocal laser scanning microscopy, and the fluorescence intensity of the images was analyzed. The optimized ethosome formulation consisted of 2.45% yolk phospholipids, 30% ethanol, and 67.55% distilled water. The percutaneous permeation of Rhodamine B in the optimized ethosomes was superior to that in hydroethanolic solution ( P <0.05) and liposomes ( P <0.05). The ethosomes could penetrate the skin via the percutaneous pathway of the hair follicle and stratum corneum, while during the process of penetration, the vesicles were broken and the phospholipids were retained in the upper epidermis, with the test compounds penetrating gradually. The superior percutaneous penetration of ethosomes was linked to the synergistic effects of their ingredients. The percutaneous pathways of ethosomes included open hair follicles and stratum corneum pathways. In addition, the vesicles might break up during percutaneous penetration in the superficial layer of the skin, allowing the test compounds to keep permeating into the deeper layer alone, while the phospholipid was retained in the upper epidermis.

NIR‐Emitting Gold Nanoclusters–Modified Gelatin Nanoparticles as a Bioimaging Agent in Tissue

“…This renders the choice of a suitable fluorophore, with a distinct fluorescence from that of skin, not an easy option, especially due to the broad emission spectrum of skin. Even with suitable dyes, offsetting the skin's fluorescence was the solution used by different research groups for imaging of NPs in skin . However, the ability to image NPs together with skin structure will give visual evidence about the NP penetration within the tissue.…”

Stable Liposome in Cosmetic Platforms for Transdermal Folic acid delivery for fortification and treatment of micronutrient deficiencies

“…Rh-B-loaded liposomes were applied to rat skin for permeation as described in above. Transverse sections of the treated area of skin were sliced using microtome (~10 µm thickness) to generate XZ-planar optical cross-sections and scanned under a confocal laser scanning microscope (Olympus IX 81 with FV 500) for fluorescence signals with an argon laser beam with excitation at 488 nm and emission at 560 nm for Rhodamine-B 28 . The depth of liposome penetration was calculated from the confocal images captured in the XY-plane of the sections (perpendicular to the plane of skin surface).…”

Comparison of the metabolism of 10 chemicals in human and pig skin explants

“…It has been reported that propyl paraben is converted to several metabolites (Abbas et al, 2010;Bando, Mohri, Yamashita, Takakura, & Hashida, 1997;Jewell et al, 2007). It can be directly conjugated to form propyl paraben-sulfate and glucuronide; or conjugates can be formed after ester cleavage to 4-hydroxybenzoic acid.…”