International Journal of Pharmaceutics 308 (2006) 155–159 Incorporation of the sunscreen agent, octyl methoxycinnamate in a cellulosic fabric grafted with -cyclodextrin Santo Scalia a,∗ , Rosanna Tursilli a , Anna Bianchi a , Pierandrea Lo Nostro b , Eugenio Bocci b , Francesca Ridi b , Piero Baglioni b a Department of Pharmaceutical Sciences, University of Ferrara, via Fossato di Mortara, 44100 Ferrara, Italy b Department of Chemistry and CSGI, University of Florence, 50019 Sesto Fiorentino, Italy Received 3 August 2005; received in revised form 25 October 2005; accepted 5 November 2005 Available online 15 December 2005 Abstract The aim of the study was to investigate the incorporation of the sunscreen agent, octyl methoxycinnamate into cyclodextrin cavities covalently bound to cloth fibres. Tencel, a cellulosic fabric, was grafted with -cyclodextrin molecules through reaction with monochlorotriazinyl-- cyclodextrin (-CDMCT). The finished and untreated textiles were soaked in water-methanol mixtures containing 2% (v/v) of sunscreen agent and subsequently subjected to several washing cycles. The unmodified and modified fabrics were characterized by UV spectrophotometry and thermogravimetric analysis. The level of octyl methoxycinnamate entrapped in the Tencel tissue was determined by high-performance liquid chro- matography and was found to be much higher (0.0203%, w/w) for the textile functionalised with -CDMCT compared to the unmodified fabric (0.0025%, w/w). In addition, spectrophotometric assessment of UV transmission through the fabric samples using the Transpore TM test showed that the in vitro sun protection factor of the textile support was markedly enhanced (3.2-fold increase) by impregnation with octyl methoxycinnamate of the -CDMCT grafted textile. Hence, even after repeated washings, the -CD finished fabric exhibits higher sunscreen agent retention and photoprotective properties than the unmodified textile material. © 2005 Elsevier B.V. All rights reserved. Keywords: Textile; -Cyclodextrin; Grafting; Sunscreen agent; Octyl-methoxycinnamate; Sun protection factor 1. Introduction The harmful effects of the solar UV radiation (290–400 nm) on human skin (i.e., erythema, cutaneous photoageing, immune suppression and various forms of skin cancers) have been the object of several studies that led to improved approaches in pho- toprotection (National Institute of Health, 1989; Gasparro et al., 1998; Green et al., 1999). The strategies advocated by health care authorities to prevent the sunlight-induced damage include reduced sun exposure, topical application of sunscreening prepa- rations and the use of proper clothing (National Institute of Health, 1989; Gasparro et al., 1998; Diffey, 2001; Gambichler et al., 2001; Edlich et al., 2004). To enhance the sun protection factor of textiles, clothes can be coated with sunscreen agents. This operation has been performed ∗ Corresponding author. Tel.: +39 0532 291277; fax: +39 0532 291296. E-mail address: sls@unife.it (S. Scalia). by adding the UV filters directly to the rinsing liquid during the laundry cycles (Edlich et al., 2004). A different approach is described in the present study for the incorporation of sunscreens into fabrics. This innovative procedure is based on cotton tissues grafted with -cyclodextrin derivatives. Cyclodextrins are toroidal-shaped cyclic oligosaccharides with a hydrophilic outer surface and an internal hydropho- bic hollow interior. Cyclodextrins can entrap a vast number of lipophilic compounds into their hydrophobic cavity, depending on their size and molecular structure. For this reason cyclodex- trins behave as hosts and the hydrophobic species are the guests. The driving force for such inclusion process is the enthalpic con- tribution that arises from non-covalent hydrophobic interactions (Loftsson and Brewster, 1996; Rajewski and Stella, 1996). This complexation phenomenon can modify some physico-chemical and chemical properties of the guest, for example enhancing its stability to oxidant agents and light and increasing its apparent aqueous solubility (Loftsson and Brewster, 1996; Rajewski and Stella, 1996; Uekama et al., 1998). 0378-5173/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.ijpharm.2005.11.007