Role of novel delivery systems in developing topical antioxidants as therapeutics to combat photoageing.

Ageing proceeds by highly complicated biochemical processes, in which the involvement of the reactive oxygen species (ROS) and free radicals has been implicated. Reactive oxygen species are dramatically enhanced by exposure to the ultraviolet radiation. Free radical scavengers and antioxidants can thus provide a long-term protection against these changes. Currently, dermaceutical and cosmetic industry is growing immensely with its main focus on packaging the active into a suitable/novel delivery system. This not only enhances the customer acceptance but offers better targeting to the upper skin layer, with faster onset, at a lower concentration of the active. Later also counter toxic or adverse effects observed with large doses especially when administered orally. Several of the antioxidant molecules are labile to degradation in the presence of oxygen, water and light, hence it becomes all the more appropriate to use a delivery system which will augment their stability and hence enhance the performance. In the present review, we focus on the pioneering research on novel delivery systems which can promote the therapeutic value of antioxidants for combating UV-induced photoageing.

Sesamol-loaded solid lipid nanoparticles for treatment of skin cancer.

Abstract Role of reactive oxygen species (ROS) in skin carcinogenesis is well documented. Natural molecules, like sesamol, with marked antioxidant potential can be useful in combating skin cancers. In vitro antiproliferative (using MTT assay) and DNA fragmentation studies in HL 60 cell lines, confirmed the apoptotic nature of sesamol. However, it showed a significant flux across the mice skin upon topical application, such that its local availability in skin is limited. Former is attributed mainly to its properties like small size, low molecular weight (138.28), and a sufficient lipid and water solubility (log P 1.29; solubility 38.8 mg/ml). To achieve its maximum epicutaneous delivery, packaging it into a suitable carrier system is thus indicated. Sesamol-loaded solid lipid nanoparticles (S-SLN) were thus prepared with particle size of 127.9 nm (PI: 0.256) and entrapment efficiency of 88.21%. Topical application of S-SLN in a cream base indicated significant retention in the skin with minimal flux across skin as confirmed by the in-vivo skin retention and ex-vivo skin permeation studies. In vivo anticancer studies performed on TPA-induced and benzo(a)pyrene initiated tumour production (ROS mediated) in mouse epidermis showed the normalization (in histology studies) of skin cancers post their induction, upon treatment with S-SLN.