JOURNAL OF COSMETIC SCIENCE 352 be necessary for reproducible stiffness test results. After combing the hair in the preparation device, the polymer/hair composite is seam-welded after drying of the polymer fi lm. The model heads for the half-side tests are sprayed and dried without combing and without any mechanical impact. Therefore the polymer/hair composite is mainly spot-welded. The different polymer/hair architecture leads to different styling grades that overcome the infl uence of the different polymers. More subjective data like salon tests and panel tests will be necessary to prove if there are differences in setting behavior that have been observed by means of the new two-point stiffness test on fl at hair strands. SUMMARY The presented two-point bending stiffness test method on fl at hair strands is a new test for measuring the bending stiffness of hair styling products. The test can be used to assess the bending stiffness of hair gels as well as hair sprays. A preparation device is used to align the hair fi bers to get reproducible results. In addition, this preparation device min- imizes the infl uence of individual processors. Results obtained with the two-point bending method on fl at hair strands are in good agreement with sensorial and consumer tests for styling gels. The correlation between the stiffness test and subjective evaluations are much closer on fl at hair strands compared to round-shaped hair strands. The best results by means of the two-point method on fl at hair strains are achieved with the combination of acrylates/beheneth-25 methacrylate copoly- mer and VP/methacrylamide/vinyl imidazole copolymer in hair styling gels. This corre- lates very well with the subjective tests on those strains. Stiffness tests on fl at hair strands after spray application using different styling polymers did not correlate with practical relevant assessments. We postulate that different poly- mer/hair composites are responsible for these discrepancies. Hairs are seam-welded in the stiffness tests after alignment of the single hairs and are spot-welded in the half-side tests on model heads after spray application without mechanical impact before the assessment of the styling performance. REFERENCES (1) F. Frosch and F. Vogel, Une méthode simple pur mesurer la fi xation des cheveux, Parfums, Cosmétiques, Arômes, 89, 71–72 (1989). (2) J. Jachowicz and R. McMullen, Mechanical analysis of elasticity and fl exibility of virgin and polymer- treated hair fi ber assemblies, J. Cosmet. Sci., 53, 345–361 (2002). (3) C. Wood and P. Hoessel, A new dimension in hairstyling—VP/methacrylamide/vinylimidazole copolymer, Cosmet. Toiletr., 119(2), 59–66 (2004). (4) P. Hoessel, J. Basilan, M. Laubender, S. Nguyen-Kim, D. Patwardhan, and B. dePotzolli, Poly- quaternium-86: Advanced styling in hair gels, SÖFW J., English Ed., 135(6), 2–10 (2009). (5) E. Pfrommer and P. Hoessel, Polyurethane-1 for VOC 55 hairsprays, Cosmet. Toiletr., 114(8), 53–60 (1999).

J. Cosmet. Sci., 61, 353–365 (September/October 2010) 353 Analysis of vitamin E in commercial cosmetic preparations by HPLC ALY NADA, YELLELA S.R. KRISHNAIAH, ABDEL-AZIM ZAGHLOUL, and IBRAHIM KHATTAB, Faculty of Pharmacy, Kuwait University, Kuwait (A.N., A.-A.Z., I.K.), and College of Pharmacy, Nova Southeastern University, Ft. Lauderdale, Florida (Y.S.R.K.). Accepted for publication May 13, 2010. Presented at the AAPS Physical Pharmacy and Biopharmaceutics Workshop, Baltimore, Maryland, May 13–15, 2009. Synopsis A specifi c HPLC method, with an RP–C-18 column and a UV detector, for simultaneous determination of vitamin E (tochopherol, T)/T acetate (TA) in four commercial and two experimental cosmetic products is de- scribed. Three solvent systems for extraction of T/TA were assessed: isopropyl alcohol 10:90 v/v hexane-methanol mixture (method 1) and methanol alone (method 2). The procedure was accurate, as indicated by high recov- ery (97.8–101.8% and 100.1–102.5% for T and TA, respectively) and precise (RSD was only 0.9–3.26% and 0.73–3.35% for T and TA, respectively). The limits of detection for T and TA were 200 and 300 ng/ml, re- spectively, while the limits of quantitation were 250 and 400 ng/ml, respectively. The range of reliable quan- tifi cation was 5–50 μg/ml. Isopropanol as solvent resulted in a turbid extract. Method 1 and method 2 of extraction showed high recovery (98.5–99.9% and 97.2–97.9% for T and TA, respectively). After a few weeks of analysis, method 1 resulted in retention time drift, peak broadening, non-reproducible results, and progres- sive loss of HPLC-column integrity. Methanol alone (method 2) was equally as effi cient as that of the mixture of methanol with 10% hexane (method 1) for extraction. The described analytical procedure proved to be ac- curate, precise, and suitable for simultaneous determination of T and TA in real commercial cosmetic products. INTRODUCTION Cosmetic changes associated with aging, especially in the face, are particularly concern- ing to the patient/consumer population that wishes to remain looking youthful all the time. Inclusion of botanical extracts such as vitamins and anti-microbials to cosmetics has become an important marketing advantage. These ingredients have the appeal of appear- ing wholesome and “organic.” Although scientifi c evidence shows that some of these in- gredients do have some in vitro anti-aging activity, the question remains as to whether it is possible to deliver adequate doses to the skin in vivo (1). Vitamin E is one of the best established ingredients in OTC products for skin aging. It is a lipid-soluble antioxidant that plays key roles in protecting cell membranes from lipid peroxidation by free radicals and in reducing photocarcinogesis (2–4). Thiele et al. concluded that α-tocopherol is the Address all correspondence to Aly Nada.