STABILITY OF PEDIATRIC SUNSCREEN EMULSION 381 Centrifugal analysis of the infl uence of temperature (4°C, 25°C) and time (0, 1, 15, and 30 days) on the stability of both the emulsion and towelette preparations showed no in- fl uence on the physical, chemical, or microbiological parameters, even in extreme condi- tions (40°C). However, the results for viscosity showed slight but insignifi cant decreases at 40°C. At this temperature, microbiological analysis also produced better results for the towelette formulation than for the emulsion. CONCLUSIONS These preliminary tests for density, dry matter, viscosity, pH, etc, demonstrate the suit- ability and uniformity of this sunscreen emulsion, and its adequate state of fl uidity in the impregnated towel formulation. It presents a pseudoplastic behavior and a stable pH, while at the same time it is not subject to signifi cant rheological or organoleptic changes, neither in the case of the emulsion nor as an impregnated towel formulation. Both formu- lations meet legal specifi cations for microbiological stability and remain unaltered under the conditions studied in this work. The sunscreen emulsion used in the towels selected for this study remained stable over time and under the conditions tested. The advantages presented by this presentation format make it an interesting proposal for future sunscreen products. REFERENCES (1) C. Soler, The skin of the newborn, El Farmacéutico, 196, 82–86 (1997). (2) E. Ledo, Photodermatosis: Photobiology, photoimnunology, and idiopatic photodermartoses., Int. J. Dermatol., 93, 387–396 (1993). (3) C. Bau and A. Pozo, Child cosmetics. II. Cosmetics with protective action, Offarm, 22-2, 161–164 (2003). (4) M. A. Pathak, T. B. Fitzpatrick, P. Nghiem, and D. S. Agasshi, “Sun-Protective Agents: Formula- tion, Effects and Side Effects,” in Fitzpatrick’s Dermatology in General Medicine, 5th ed. (McGraw-Hill, New York, 1999), pp. 2742–2763. Figure 6. Test results for the rheological properties of the emulsion.

JOURNAL OF COSMETIC SCIENCE 382 (5) M. Valdivielso, C. Mauleón, E. Balbín, P. Cueva, E. Chavarria, and J. M. Hernanz, Photoprotection in children. J. Primary Care Pediatrics, 11(42), 313–324 (2009). (6) J. Puech-Plottoya, J. L. Michel, L. Misery, and F. Cambazard, Photodermatosis and photoprotection in children, Arch. Pediatrics, 7(6): 668–679 (2000). (7) D. Williams. Chemistry and Technology of the Cosmetics and Toiletries Industries (Champan and Hall, London 1996), pp. 183–185. (8) L. Azcona, Skin care of the baby, Profess. Pharm., 19(11), 54–57 (2005). (9) R. Bonet and A. Garrote, Child photoprotection, Offarm, 27(6), 60–66 (2008). (10) M. J. Avril, Sun and Skin: Benefi ts, Risks and Prevention (Masson, Barcelona, Spain, 2004), pp. 19–24. (11) M. T. Alcalde, Sun protection glossary, Offarm 27(7), 52–58 (2008). (12) A. Bernabéu, Child photoprotection, recommendations and specifi c cosmetics, Offarm, 25(6), 59–67 (2006). (13) S. Schalka, V. Silva, and L. C. Cucé, Photodermatol. Photoimmunol. Photomed., 25, 175–180 (2009). (14) D. Marín and A. Pozo, Sunscreens: Characteristics, types and requirements, Offarm, 24(9), 175–178 (2005). (15) T. Koichi, N. Takeharu, S. Takehiro, N. Osamu, N. Fukie, I. Masaaki, E. Yasuo, S. Takumi, S. Susumu, and T. Takeshi, Anti-infl ammatory effect of propolis through inhibition of nitric oxide production on carrageenin-induced mouse paw edema, Biol. Pharmaceut. Bull., 29(1), 96–99 (2006). (16) C. Couteau, M. Pommier, E. Paparis, and LJ. Coiffard, Photoprotective activity of propolis, 22(3), 264–268 (2008). (17) EDANA, Defi nition of Non woven, ISO 9092 (1998). (18) R. Bharadwaj, A. Patel, and S. Chokdeepanich, Oriented fi ber fi lter media, J. Eng. Fibr. Fabr., 3, 29–34 (2008). (19) K. M. Brinsko. Optical characterization of some modern “eco-friendly” fi bers, J. Forensic Sci., 55(4), 915–923 (2010). (20) COLIPA, Guidelines on Stability Testing of Cosmetic Products (2004). (21) COLIPA, Guidelines for Evaluating Sun Product Water Resistance (2005). (22) L. Rigano and S. Siguri, Sensory analysis: A tool for assessing the quality of cosmetics, NCP, 215, 5–9 (1996). (23) Royal Spanish Pharmacopoeia, 3rd Ed. (Ministry of Health, Madrid, 2005), pp. 165–170. (24) Y. Eros and A. Thaleb, Rheological studies of creams, Pharmaceut. Hung., 64, 101–103 (1994). (25) G. Cáceres, Sun protection and melanoma, Offarm, 28(5), 73–80 (2009). (26) A. F. Méndez-Sánchez, L. Pérez-Trejo, and A. M. Paniagua Mercado, Determination of the viscosity of fl uids Newtonian and non-Newtonian, Lat. Am. J. Physics Ed., 4(1), 237–245 (2010).