Release of vitamin e from different topical formulation systems and their in vitro-in vivo evaluation

The aim of this thesis study entitled `Release of Vitamin E From Different Topical Formulation Systems and Their In vitro - In Vivo Evaluation? was to prepare topically applicable microemulsion, macroemulsion, solid lipid nanoparticle (SLN) and molecularly imprinted polymer (MIP) cosmetic delivery systems, to add the antioxidant vitamin E to those systems and in vitro and in vivo comparison of the systems. Vitamin E is known to be an antioxidant by scavenging the free radicals and leads to an antiaging effect. Within the scope of this study, o/w microemulsion, macroemulsion, SLN and MIP systems containing vitamin E were developed. Caprilic acid ester was the oily phase and Tween® 80 was the surfactant used in both emulsion systems; in the microemulsion system, PEG 400 was used as the co-surfactant. In the SLN system, Compritol® ATO 888 was used as the solid lipid, while Tween® 80 was used as the surfactant. In the MIP formulation, ?-tocopherol was the template, ß- cyclodextrine was the polymer, hexamethylenediisocyanate (HMDI) was the cross-linking agent and the dimethylsulfoxide (DMSO) was the porogen. Antioxidant effects of formulations prepared were investigated by 2,2-diphenyl-1- picrilhydrasil (DPPH) test and compared. Quantification of vitamin E and release properties of formulations were determined using Franz diffusion cells. In the stability tests, possible changes in phase inversion, pH, physical appearance, droplet size and conductivity were followed after storing the formulations at various conditions. Formulations with vitamin E were applied on ten volunteers for a duration of one month and skin measurements were repeated once a week. Skin measurements included sebum, moisture, pH, net elasticity and roughness parameters. Vitamin E could be incorporated into all formulations successfully. All formulations showed antioxidant activity. The o/w microemulsion prepared was superior to macroemulsion, SLN and MIP system according to stability and physical properties. KEY WORDS: Vitamin E, Microemulsion, Macroemulsion, Solid Lipid Nanoparticle, Molecularly Imprinted Polymer, Cosmetic Application