Product (Brand name) Active ingredients Company SPF PA factor (UVA coverage) Ref. (website) Hyclean Octinoxate, oxybenzone Ranbaxy Laboratories Ltd. - - (99) Melalite 15 cream Hydroquinone, octinoxate, oxybenzon Piramal Health care SPF 15 - (100) Vanicream Titanium dioxide, zinc oxide Pharmaceutical Specialties, Inc. SPF 50+ Broad spectrum but PA factor not mentioned on the label, conforms to the maximum quantity of water resistance (80 minutes) (101) Vanicream Sunscreen Sport Zinc oxide, octinoxate Pharmaceutical Specialties, Inc. SPF 35 Broad spectrum but PA factor not mentioned on the label, meets the maximum amount of water resistance (80 minutes) (102) Table IV Continued UV PROTECTION AND EVALUATION OF EFFICACY OF SUNSCREENS 339

JOURNAL OF COSMETIC SCIENCE 340 the UVA protective effi cacy of the test product depending on the type of appropriate source and biological action spectrum (104). Hojerová et al. (2011) assessed photostability of 15 products using three indicators, that is, AUCI for the total UV range, and UVB, UVA, UVA2, UVA1 range separately and the re- sidual effectiveness of in vitro SPF and UVA-PF. All sunscreens were photostable in the 15 UVB region. Seven products exhibited photoinstability in the total UV range (290–400 nm) all of them contained a combination of the ethylhexyl methoxycinnamate (EHMC) and butyl- methoxydibenzoylmethane (BMBM) together with other UV fi lters. Eight products lacked their stability in the UVA1 range (340–400 nm), thus confi rmed that photodegradation of some current sunscreens is primarily a problem of this region. Sunscreens S1 (EHMC, BMBM, and phenylbenzimidazole sulphonic acid) and S6 (EHMC, BMBM, phenylbenzimidazole sul- phonic acid, and ethylhexyl triazone [EHT]) showed maximum photoinstability and their AUC-UVA1 Index was 0.15 only. Excellent UVA1 photostability was shown by sunscreen S8 (EHMC, EHT, and methylene bis-benzotriazolyl tetramethylbutylphenol) and its AUC- UVA1 Index was 1.00. Three sunscreens showed very good UVA1 photostability (AUC- UVA1 Index ranged from 0.98 to 0.93). Comparison of the residual usefulness of in vitro SPF and UVA-PF values with the AUC-Index showed that methods give a similar ranking of the sunscreen’s photostability (105). Hence, photostability studies should be a mandatory require- ment before the marketing of sunscreen for a safer and better sunscreen protection. WATER RESISTANCE TEST In vitro test has been performed by few International industries for evaluating water resis- tance of sun blockers. The test involved assessing SPF of sunscreens before and after water immersion and then determining percentage of SPF retention. If SPF resistance is more than 50%, then the product is marked as water resistant, otherwise not. The products were applied to polymethyl methacrylate (PMMA) plates in place of skin. According to the investigators, conductivity of water affects the water resistance of the products. Ahn et al. (2007) also determined in vitro water resistance test and concluded that rate of fl ow of water for washing off the product from substrate and strength or properties of substrate are critical parameters. According to the investigations, stirring rate of 150 rpm for 60 min simulated suffi cient in vivo conditions (106). %WRR = [SPFwet − 1]/[SPFdry − 1] × 100% where, WRR = water resistance retention SPFwet = SPF after water immersion and SPFdry = SPF before water immersion. In the United States, in vivo determination involves the ability of a product to withstand water immersion for 20 min, and SPF should not change. Very or extra water resistant products should offer the same protection after four cycles of 20-min immersions. Each immersion cycle is followed by a 20-min rest and an air dry period until the total water exposure time is reached. According to European guidelines, SPF after a 40- and 80-min water immersion period is compared to the original SPF before water exposure. The prod- uct is declared as water resistant or extra water resistant if SPF after 40- or 80-min im- mersions, respectively, is greater or equal to 50% of the pre-immersion SPF. Consequently, SPF number specifi ed on label for European sunscreen products is pre-water exposure,