Showing papers by "Joke A. Bouwstra published in 1994"
TL;DR: It is concluded that liposomes and niosomes may become a useful dosage form for a variety of dermally active compounds, specifically due to their ability to modulate drug transfer and serve as nontoxic penetration enhancers.
521 citations
TL;DR: Two mechanisms are proposed to play an important role in vesicle–skin interactions, i.e., the penetration enhancing effect of surfactant molecules and the effect of the vesicular structures that are most likely caused by adsorption of thevesicles at the stratum corneum–suspension interface.
Abstract: The permeation of estradiol from vesicular formulations through human stratum corneum was studied in vitro. The vesicles were composed of nonionic n-alkyl polyoxyethylene ether surfactants (CnEOm). The thermodynamic activity of estradiol present in each formulation was kept constant by saturating all formulations with estradiol. The effects of both the particle size and the composition of the formulation on estradiol permeation across excised human stratum corneum were investigated. Stratum corneum that was pre-treated with empty surfactant carriers allowed for significantly higher estradiol fluxes compared with untreated stratum corneum. However, estradiol fluxes obtained in these pretreatment experiments appeared to be significantly lower than those obtained by the direct application of the estradiol-saturated carrier formulation on top of the stratum corneum. Furthermore, in the case of pretreatment of the stratum corneum, an increase in carrier size resulted in a decrease in estradiol flux. For direct application the opposite was found. Two mechanisms are proposed to play an important role in vesicle–skin interactions, i.e., the penetration enhancing effect of surfactant molecules and the effect of the vesicular structures that are most likely caused by adsorption of the vesicles at the stratum corneum–suspension interface.
124 citations
TL;DR: The structure of mouse stratum corneum was investigated using small and wide angle X-ray scattering and it was concluded that the size of the crystallographic unit cell of the lipid structure is insensitive to the water content.
123 citations
TL;DR: Cardiolipin with divalent cations can replace the role of phosphatidylethanolamine in the mutant strain, and that this role involves the preference of these lipids for organization in non-bilayer lipid structures.
65 citations
TL;DR: It was concluded that the subzero transition (−9°C) belongs to low melting lipid components of stratum corneum.
Abstract: The thermal behaviour of human stratum corneum was studied using differential thermal analysis within the temperature range of −130°C to 120°C. Aside from thermal transitions at around 40°C, 70°C, 85°C and 100°C, which have been reported before, a particular transition below 0°C (subzero), at approx. −9°C (264 K), was noticed. This transition was present in the analysis curves of dehydrated as well as hydrated stratum corneum sheets and could be distinguished from the water peak found only in hydrated stratum corneum samples. To further characterize this transition, thermal analysis was performed on stratum corneum sheets: (i) after lipid extraction, (ii) after pre-treatment of propylene glycol and (iii) after pretreatment of oleic acid/propylene glycol solution. From the results, it was concluded that the subzero transition (−9°C) belongs to low melting lipid components of stratum corneum.
26 citations
1 citations
1 citations
TL;DR: In this article, the authors studied the thermal behavior of stratum corneum using differential thermal analysis within the temperature range of −130°C to 120°C and found that a particular transition below 0°C (subzero), at approx. −9°C(264 K), is present in the analysis curves of dehydrated as well as hydrated stratum Corneum sheets and could be distinguished from the water peak found only in hydrated Corneum samples.