No abstract

No abstract

Alpha-tocopherol, or vitamin E (VE), is widely used as a strong antioxidant in many medical and cosmetic applications, but is rapidly degraded, because of its light, heat and oxygen sensitivity. Thus, all of its formulation has to avoid contact with light, heat or air. Drug loaded carriers are an attractive opportunity, especially if they are made for bioacceptable macromolecules such as vegetal proteins. For instance, gliadins, extracted from wheat gluten, generate nanoparticles by a desolvatation method and may interact with epidermal keratin for therapeutic or cosmetic formulations. Their lipophilic drug loading capacities have been investigated. The VE loaded gliadin nanoparticles have been characterized by their size, by their zeta potential, by their VE payload, and by their entrapment efficiency. When VE loaded, the gliadin particle size is approximately 900 nm and their charge is close to zero. They are suitable VE drug carriers with an optimum encapsulation rate approximately 100 VE microg/gliadin mg with an efficiency of more than 77%. The release behaviour of VE loaded nanoparticles may be interpreted as a 'burst effect', followed by a diffusion process through an homogeneous sphere.

No abstract

: Gliadin nanoparticles were prepared by a desolvatation method. They showed good stability during several weeks in PBS or aqueous medium. Assayed as carriers for all-trans-retinoic acid (RA), they have a quite good entrapment efficiency : about 75% of added drug at (mg gliadin)-1 and a 60 lgp ayload of (mg gliadin)-1 nanoparticles. A rapid release of 20% of the drug after 15 min in sink 76.4 lgc onditions and a diþ usion process in a second step are observed. According to the nature of vegetal proteins, the size control of the nanoparticles may be reached by varying the nature of the solvent, the pH and the ionic strength. Because gliadin is poorly solubilized in aqueous solutions, the ürst method was chosen. In order to quantify more precisely the solvent eþ ect, the size diameter was optimized through a solubility parameter study. The smallest size was reached for protein solubility solvent equal to that of gliadin. Size diþ erences were observed with respect to the process steps ; the diameter obtained after nanoprecipitation ýuctuates with time.1999 Society of Chemical Industry (