,, Cl) "' C'G "'i � 120 100 80 60 40 20 0 COSMETIC FORMULATIONS WITH ARGIRELINE® 169 15 30 45 Time (min) 60 90 ■ Cream 4° C D Cream 25° C Gel 4° C □ Gel 25° C Figure 8. Release without membrane of the Argireline® samples maintained at 25 ° and 4°C. The gel formulation showed evidence of thermal gelling during the first 15 days of storage after preparation, and this reduced diffusion of the peptide from sam­ ples stored at 25 ° C. The results of in vitro assays confirmed that the active prin­ ciple penetrated the artificial membrane and that it is a suitable delivery from both excipients. 100 80 -a-CREAM --l:r-GEL Q) 60 Q) 40 0 20 0 0 1 2 3 4 5 6 7 Time (hours) Figure 9. Percentage of Argireline® released from the gel and cream as a function of the time.

170 JOURNAL OF COSMETIC SCIENCE 60 - C) 50 0 E - "C 40 Q) 30 Q) � __, 20 C ---CREAM � 10 ---tr- GEL 0 0 1 2 3 4 5 6 7 Time (hours) Figure 10. Amount of Argireline® released as a function of the time for the two tested samples. ACKNOWLEDGMENTS Part of this work was supported by the Spanish Ministry of Education and Science and by European Regional Development Funds under Project MAT2005-07746-C02-02 and Project of Excellence FQM 410. We thank K. Shashok for translating parts of the original manuscript into English. REFERENCES (1) G. C. Singh, M. C. Hankins, A. Dulku, and M. B. Kelly, Psychosocial aspects of botox in aesthetic surgery. Aesthetic Plast. Surg., 30, 71-76 (2006). (2) G. Peyrefitte, Biologfa de la Piel (Masson, Barcelona, 1995), pp. 65. (3) M. T. Alcalde and A. Pozo, Fondos de maquillaje I., Of/arm, 22, 161-162 (2003). (4) S. J. Stegman, T. A. Tromovitch, and R. G. Glogau, The Skin of the Aging Face in Cosmetic Dermatologic Surgery, 2nd ed. (Mosby Year Book, St. Louis, Mo., 1990), pp. 5-15. (5) B. Alberts, D. Bray, and J. Lewis, Biologfa Molecular de la Celula (Ediciones Omega, Barcelona, 1996), pp. 572-577. (6) L. M. Gutierrez, S. Viniegra, J. Rueda, A. V. Ferrer-Montiel, J.M. Canaves, and M.A. Montal, A peptide that mimics the C-terminal secuence of SNAP-25 inhibits secretory vesicle docking in chrornaffin cells,]. Biol. Chem., 272, 2634-2638 (1997). (7) P. M. Becker-Wegerich, L. Rauch, and T. Ruzicka, Botulinum toxin a successful decollete rejuvena­ tion, Dermatol. Surg., 28, 168-171 (2002). (8) V. Benedetto, The cosmetic use of botulinum neurotoxin type A, Int.]. Derm., 38, 641-655 (1999). (9) C. Blanes-Mira, J.M. Merino, E. Valera, G. Fernandez-Ballester, L. M. Gutierrez, S. Viniegra, E. Perez-Paya, and A. Ferrer-Montiel, Small peptides patterned after the N-terminus domain of SNAP 25 inhibit SNARE complex assembly and regulated exocytosis,J. Neurochem., 88, 124-125 (2004). (10) A. V. Ferrer-Montiel, L. M. Gutierrez, J.P. Apland, J. M. Canaves, A. Gil, S. Viniegra, J. A. Biser, M. Adler and M. Montal, The 26-mer peptide released from 25 by botulinum neurotoxin E inhibits vesicle docking, FEBS Lett., 435, 84-88 (1998). (11) C. Blanes-Mira, A. Jodas, A. Gil, G. Fernandez-Ballester, B. Ponsati, E. Perez, and A. Ferrer-Montiel, A synthetic hexapeptide (Argireline®) with antiwrinkle activity, Int.]. Cosmet. Sci., 24, 303 (2002). (12) L. Rigano and S. Siguri, Analisis sensoriales: Un instrumento para determinar la calidad en cosmetica, NCP, 215, 5-9 (1996).