2010 TRI/PRINCETON CONFERENCE 165 recorded as counts per second. Samples for XRF analysis are prepared by cutting each treated hair tress into 1.5-cm lengths and placing the cut lengths into a sample cup hav- ing a 6-μm thick polyethylene support substrate formed into the bottom. A polyethylene spacer is placed on each cut tress to hold it onto the substrate. Three tresses per formula- tion are measured. Sensory panel testing. Two-in-one conditioning shampoo formulations are compared by a trained panel (at least three panelists) for conditioning attributes using a forced choice test design between two treated hair tresses. Hair tresses treated with a conditioning shampoo formulation (Formulation A) are compared to hair tresses treated with another shampoo formulation (Formulation B). Each panelist is asked to indicate which tress performs better for each of fi ve sensory attributes evaluated in comparing the two test formulations on the treated hair tresses. The sensory attributes evaluated by the panel include ease of wet combing, wet feel (soft feel or wet conditioned feel), ease of dry comb- ing, dry feel (soft feel or dry conditioned feel) and static buildup (fl yaway). The test pro- tocol utilizes a matrix design of six treated tresses (three replicates for each of test Formulations A and B). The test matrix allows for the direct blind comparison of the 3 replicate treated tresses of Formulation A versus the 3 replicate treated tresses of Formu- lation B. By permutation of the 3 replicate treatments for each of Formulations A and B, nine comparisons of paired tresses (Formulation A versus Formulation B) are possible. The matrix is designed such that duplicate evaluations are included from the panel mem- bers. A total of 36 comparisons are carried out with the matrix design. A statistical analysis (Z-value calculation by exact binomial test, of preference of Formulation A versus Formulation B) is used to determine the level of confi dence that Formulation A is statis- tically different (better or worse for the selected sensory attribute) from Formulation B. Formulations. Each shampoo formulation contains surfactant levels as described in the design of experiments in Figure 1. The formulations also contain a fi xed amount of NaCl at 1.0 wt% and fi xed amount of cationic polymer (either EX-906 or EX-1086) at 0.25 wt%. The pH is adjusted with citric acid to pH =7 in all cases. For the silicone deposition and sensory performance analyses, 2 wt% of Dow Corning® 2-1352 silicone emulsion (0.5 μm) is added to the formulation. All wt% values indicated in this study are based on an active content. RESULTS AND DISCUSSION COACERVATION PROFILES The coacervation profi les are recorded by measuring the change of formulation clarity with dilution ranging from 0 to 30 for each stable formulation. The coacervation curves generated for the various surfactant blend compositions with each cationic cassia polymer are found in Figures 4 and 5. The results show that the surfactant composition has a strong infl uence on the coacervation profi les. The coacervation profi les of both cationic cassia polymers can be extended to higher dilution range by changing the amount of SLES-3, SLS or CAPB. Consequently, the amount of coacervate formed over a dilution of 0 to 30 varies greatly. This amount can be quantifi ed by integrating the area contained between the curves and the 100% transmittance horizontal line. The area is calculated by trapezoid numerical integration from dilution 0 to 30 and is reported as the calculated coacervation area in Table I and Table II.

JOURNAL OF COSMETIC SCIENCE 166 DEPOSITION RESULTS Silicone deposition on European brown hair and the cationic polymer deposition on wool swatch were measured for both cassia polymers. The average results for the net silicon in- tensity for EX-906 for various surfactant blends and various amount of coacervate formed is reported in Figure 6. The results show that the amount of silicone deposited on the hair varies largely with the surfactant blend composition, and little correlation is observed be- tween the amount of silicone deposited on the hair and the amount of coacervate formed. Higher amounts of coacervate formation (i.e., by broadening of the coacervation profi le to higher dilution range) do not lead to higher level of silicone deposition. This result is unex- pected as literature results indicate that the formation of higher amounts of coacervate of broadening of coacervation profi les leads to higher silicone deposition (12,13). The cationic polymer deposition on wool was measured by Direct Red 80 dye titration by spectrophotometry as previously described. The results for EX-906 are summarized in Figure 7 and show only a slight change in the amount of cationic cassia polymer depos- ited on the wool with different surfactant blend compositions. As similarly seen in the silicone deposition results, there is no correlation between the amount of cationic cassia polymer deposited on wool and the amount of coacervate formed with the various surfac- tant blend compositions. The correlation between the EX-906 cationic cassia deposition on wool and the silicone deposition on hair is illustrated in Figure 8. The data show that there is a relatively good correlation between the cationic cassia EX-906 polymer deposition Figure 4. Coacervation profi les for EX-906 (3.0 mEq/g). Figure 5. Coacervation profi les for EX-1086 (1.7 mEq/g).