2001 ANNUAL SCIENTIFIC MEETING 65 .F!.g..3='.C._o.o.mparison of data and images under visible and invisible information. "' ' ......... • •':'='-: .......... • -•1 :: ......... _• • • • .• - Fig. 4: Correlation of facial wrinkles measured by the image analysis and visual grading. Correlation between wrinkle area fraction and visual grading y = 0.0022x + 0.0251 r=0,8665 0.00 20.00 40.00 60.00 80.00 100.00 Visual grading score

66 JOURNAL OF COSMETIC SCIENCE Pl•SSUl• SENSITIVE ADHESIVE SYSTEMS FOR TOPICAL AND TRANSDERMAL COSMETIC APPLICATIONS Scott D. Barnhart Adhesives Research, Inc., Glen Rock, PA Frequently utilized in the medical and pharmaceutical industry, skin-friendly pressure sensitive adhesives (PSA's) provide a clean, efficient vehicle for transdermal and topical delivery systems. This coating technology platform can be leveraged to deliver active or inactive cosmetic ingredients, many ingredients of which have been applied to the skin from traditional creams, ointments, and lotions. PSA's and specialty coatings are available in many forms, including substrate/adhesive laminate, unsupported adhesive transfer films, and tackless dissolvable films to name a few. Figure 1 provides examples of various adhesive tape constructions. Pressure sensitive adhesive chemistry draws upon a range of polymers including rubber/resin systems, acrylic copolymers, silicones, and advanced polymer blends. The substrate/adhesive constructions are unique combinations that, through the proper selection of components, lend themselves well to cosmetic applications. Figure 1 "P:&& T&pl ConttructlGnt Transfer •A dkesives ll Single.Faced Tapes D ouble-Faced Tapes Continuing research and development in the application of pressure sensitive adhesives and specialty coatings have produced unique, innovative topical delivery options. Coating chemistries now exist that may allow for the incorporation of an ingredient into a polymer system that was not previously possible. Or, these new chemistries may enhance specific applications whereby rapid transmission of a selected ingredient is facilitated to the skin surface •, moisture management is improved, or "smart" coatings may display activatable/deactivatable adhesion properties? Through the use of graft copolymer technology, it is possible to impart hydrophilic or hydrophobic properties onto a polymer molecule. Grafting the specific property to the polymer creates a unique material that does not phase separate into discreet groups of molecules in bulk, which would be the case if each individual component were simply mixed together, but rather forms small phase domains that are rich in either the graff or the main chain polymer. Due to covalent bonding during copolymerization, the graff is bound to the main polymer chain. Examples of unique properties include hydrophilic character imparted onto a relatively hydrophobic polymer, inhibition of crystal formation in a polymer system that otherwise would exhibit limited solubility of a solute, and improvements to the cohesive strength of an adhesive that is susceptible to dissolution by an excipient.