Non-ionic surfactant vesicles as a carrier system for dermal delivery of (+)-Catechin and their antioxidant effects

Numerous skin disorders and diseases are related to oxidative stress. The application of an antioxidant, serving as a strong defense agent against oxidation, is of great interest in dermatology yet remains challenging for delivery. This paper aimed to develop a niosome carrier system to deliver the antioxidant (+) Catechin into the skin. (+) Catechin-loaded niosomes were prepared using film hydration technique and the physicochemical properties of drug-loaded niosomes were characterised and investigated by a series of in vitro and ex vivo studies. The optimised formulation displayed an acceptable size in nanoscale (204 nm), high drug entrapment efficiency (49%) and amorphous state of drug in niosomes. It was found that (+) Catechin-loaded niosomes could effectively prolong the drug release. Drug deposition in the viable layers of human skin was significantly enhanced when niosomal carriers were applied (p < 0.05). Compared to the pure drug, the niosomal formulation had a greater protective effect on the human skin fibroblasts (Fbs). This is consistent with the observation of internalisation of niosomes by Fbs which was concentration-, time- and temperature-dependent, via an energy-dependent process of endocytosis. The research highlighted that niosomes are potential topical carriers for dermal delivery of antioxidants in skin-care and pharmaceutical products.

Solute-vehicle-skin interactions in percutaneous absorption: the principles and the people

An appreciation of solute-vehicle-skin interactions underpins our current understanding of the processes of percutaneous absorption as well as in the prediction of the extent of absorption. This understanding has been reached through principles developed and validated over the last century through the work of a number of authors, including Dale Wurster, Takeru Higuchi, Irvin Blank, Robert Scheuplein, Gordon Flynn, Boyd Poulsen and Tom Franz, as well as by many scientists from my and younger generations. Their work has led to an appreciation of the rate-limiting steps in percutaneous penetration, the role played by the physicochemical properties of the solute, vehicle and skin and the variability that may arise from using various experimental/mathematical/pharmacokinetic models to quantify absorption as well as enabling the prediction of local and systemic efficacy and toxicity. In addition, unexpected behaviour may result from non-ideality in solute-vehicle-skin effects, including dehydration, chemical enhancement, supersaturation, metabolism, sequestration and vascular effects, including those of nanosystems on the local vasculature. In general, in vitro skin penetration profiles are predictive of in vivo profiles but a number of exceptions also exist.

Liposomes and niosomes as potential carriers for dermal delivery of minoxidil

The aim of this work was to formulate minoxidil loaded liposome and niosome formulations to improve skin drug delivery. Multilamellar liposomes were prepared using soy phosphatidylcholine at different purity degrees (Phospholipon 90, 90% purity, soy lecithin (SL), 75% purity) and cholesterol (Chol), whereas niosomes were made with two different commercial mixtures of alkylpolyglucoside (APG) surfactants (Oramix NS10, Oramix CG110), Chol and dicetylphosphate. Minoxidil skin penetration and permeation experiments were performed in vitro using vertical diffusion Franz cells and human skin treated with either drug vesicular systems or propylene glycol-water-ethanol solution (control). Penetration of minoxidil in epidermal and dermal layers was greater with liposomes than with niosomal formulations and the control solution. These differences might be attributed to the smaller size and the greater potential targeting to skin and skin appendages of liposomal carriers, which enhanced globally the skin drug delivery. The greatest skin accumulation was always obtained with non-dialysed vesicular formulations. No permeation of minoxidil through the whole skin thickness was detected in the present study irrespective of the existence of hair follicles. Alcohol-free liposomal formulations would constitute a promising approach for the topical delivery of minoxidil in hair loss treatment.

Enhancement Effect ofp‐Menthane‐3,8‐diol on In Vitro Permeation of Antipyrine and Indomethacin Through Yucatan Micropig Skin

The enhancing effect of p-Menthane-3,8-diol (MDO) on skin permeation of antipyrine (ANP) and indomethacin (IM) through Yucatan micropig skin in vitro was compared with 1-menthol. p-Menthane-3,8-diol is a metabolite of 1-menthol and has little odor. It is easy to combine the vehicle because of lower lipophilicity than 1-menthol. All formulations contained 40% (v/v) ethanol. The permeation of ANP increased with MDO about three times that without enhancer by increasing ANP concentration in the skin. However, the MDO effect was about a quarter that of 1-menthol. The permeation of IM with MDO was about 15 times that with no enhancer and it was almost the same as that with 1-menthol. The lag time of permeation was not significantly changed by MDO, which was not so in the case of 1-menthol. Skin concentration of IM increased about 11 times and six times with MDO and 1-menthol, respectively. MDO and 1-menthol partitioned to the skin relatively high concentrations, 5.9 and 2.5 mg/ cm3, respectively. The solubility of IM in the skin was improved by MDO, and consequently, the permeation of IM was enhanced.