418 JOURNAL OF COSMETIC SCIENCE SPF/%Ti02 ,.,, . ... u 3.31 0.11 2.2t 1.IS 2.05 CrHlcal Lambda '11M u-.n - �· :m, 312.A 311.1 376.36 374.1 UVA/UVB .... '.M.'.' ..... o.sot 0.454 0.762 0.751 G.533 o.511 SPF Change - (♦) 46'1(. (+) 1-lr.� - ( ) f2'1i, SPF/%TI02 ·1,M'. 1.11 . --NIA NIA 2.03 1.29 1A2 .. 1.7 Crltlcal Lambda ,.... ,,. tll.1 NIA NIA 378.45 Sl1� 'S74.7 373,0,5 UVA/UVB DAIi U11 NIA NIA 0.112 0.701 0.491 G.41 SPF Change ( )31.1% (·)3". (♦)19.7% SPF/%Ti02 ue UI 1.111 2.75 _3� 3.17 1.73 1.05 Critical Lambda ... ..... 373 372 - 371.55 371.8 371.8 UVA/UVB .... Ml 0.414 0.414 0.701 o.� 0.54e G.624 SPF Change (♦)� (+)45.5% ( )11% ( -) 39.3'- Table 3. Sunscreen performance properties using powders versus formulated dispersions Formulation processing also has effects on the final efficacy of product films. In some cases the location of the particles is governed by order of addition so that a hydrophilic dispersion for example (3) easily disperses in a high surfactant O/W but is not homogeneous in an inverse emulsion or a less hydrophilic system as the gel network. Best results in these systems are achieved with direct addition to the oil phase of hydrophobic dispersions. See Table 4 below. TI02 as powder vs Dispersion SPF/%Ti02 Crltlcal Lambda UVA/UVB SPF Change ....... 0.11 ......... 312.A 2.21 381.85 1.51 381.2 0.705 (•)25.� TIOi Dl.,,.,.ion (4) (4)1noU (4)added 1.13 375.35 0.533 1A2 374.7 0.411 phaN last 2,05 1.51 371.1 1.7 1.74 373.0.5 373.35 0.47 (+) 197%

2004 ANNUAL SCIENTIFIC SEMINAR 419 SPF/% Ti02 2.34 2.11 U3 3.56 3.17 3.08 1.73 1.05 0.71 Critical Lambda 317.31 .... 370.2 310 379.51 3I0.2 371.1 371.8 37'.05 -- UVA/UVB UM 0.48 0.437 0.701 0.703 0�709 O.MI 0..514 0,531 SPF Change (t)2U%. (·) 0.S'lft ( ·} 11'- ,� ( : 13;5� (·)39.3% (-) 59"4 Table 4. Comparison of powder performance versus addition of dispersions to oil phase or final emulsion Looking more closely at the amphiphilic dispersion of the hydrophilic Titanium Dioxide in the amphisoluble polyether, PEG 7 Methyl Ether, optimal performance occurs with addition to the emulsion continuous phase favoring effective dispersion in the outer phase with less dependence on emulsion breakdown on skin and coalescence of sunscreen micropigment laden droplets. See Table 5.below. Properties SPF/%Ti02 Critical Lambda UVA/UVB SPF/% Ti02 Critical Lambda UVA/UVB SPF/% TI02 Critical Lambda UVA/UVB Table 5. Dispersion of Hydrophilic Titanium Dioxide in Polyether (PEG 7 Methyl Ether) Performance of polyether dispersion is significantly better in hydrophilic O/W emulsion but not in gel network or inverse water-in-silicone emulsion. See Table 6. below