JOURNAL OF COSMETIC SCIENCE 94 at 33°C while shaking at 220 rpm to cover exposed adhesive. Fluid was removed from each well and washed three times with KP, and then 1.0 ml of C. albicans suspension (105 CFU/ml) and 1.0 ml of TSB were added to each tape strip. The plates were incubated at 33°C for 60 min, the fl uid was aspirated, and the tape strips were rinsed three times with 3.0 ml TBS. CMC (3–4 μm) was suspended (0.25 mg/ml) in each of the following buffers: citrate phosphate (0.1 M pH 4.2, 5.2, and 6.2) TRIS (0.1 M pH 7.2 and 8.2) 4-(2-hydroxyethyl)- 1-piperazineethanesulfonic acid (HEPES) (50 mM pH 6.2, 7.2, and 8.2) or phosphate (50 mM pH 6.2, 7.2 and 8.2). A 2.0 ml sample of each CMC solution was added to one well containing a prepared tape strip, and 2.0 ml of each buffer without CMC were used as controls. The tape strips were then incubated at 25°C while shaking at 220 rpm. At 10-min time intervals after addition of the CMC or buffer control solutions, selected tape strips were rinsed three times with 3.0 ml DI water and fi xed by incubating 2.0 ml of 2.5% glutaraldehyde with each sample for 10 min. The samples were then rinsed three times with 3.0 ml of DI water and stained using 0.5 ml calcofl uor white for 10–15 min. The tape strips were again rinsed three times with 3.0 ml DI water and allowed to air dry. Once the tape strips were dry, the yeast cells were counted microscopically and the per- cent removal calculated using the method and formula described previously. DETERMINATION OF C. ALBICANS GROWTH INHIBITION BY CMC C. albicans (2.0 ml 2 × 105 CFU/ml) in PBS was incubated with either 2.0 ml of 3–4 μm CMC suspension (0.5 mg/ml) or 3–4 μm cellulose–phosphate suspension in TBS (0.5 mg/ml pH 7.2) for 210 min at 33°C. Fluid samples (1 ml) were collected at 0, 15, 30, and 60 min time intervals and plated (in triplicate) on SAB-DEX agar. The agar plates were incubated for 24 h at 33°C and the resulting colonies were counted. PRETREATMENT OF SKIN TAPE STRIPS WITH CMC Tape strips were prepared and the exposed adhesive was blocked with 5% BSA as previ- ously described. Each tape strip was treated with 2.0 ml 3–4 μm CMC suspension (0.25 mg/ml) in TBS for 15 min at 25°C at 220 rpm and then rinsed three times with 3.0 ml TBS. Next, 1.0 ml each of C. albicans suspension (105 CFU/ml) and TSB were added to each tape strip and incubated at 33oC for 60 min. The fl uid was aspirated and the tape strips were rinsed three times with 3.0 ml of TBS. Each tape strip was then fi xed with 2.0 ml of 2.5% glutaraldehyde for 10 min at 25°C while shaking at 220 rpm. The tape strips were then rinsed three times with 3.0 ml of DI water and stained with 0.5 ml calcofl uor white for 10 to 15 min. The tape strips were again rinsed three times with 3.0 ml DI water and allowed to air dry. Once the tape strips were dry, the attached yeast cells were counted microscopically. SIMULTANEOUS ADDITION OF YEAST AND CMC TO SKIN TAPE STRIPS Tape strips were prepared and blocked with 5% BSA as previously described. Each tape strip was then treated with 1.0 ml each of 3–4 μm CMC (0.5 mg/ml) and C. albicans

RELEASE OF C. ALBICANS FROM SKIN 95 (105 CFU/ml) suspensions in TBS. The control was treated with C. albicans and TBS without 3–4 μm CMC. The tape strips were incubated for 1 h at 33oC while shaking at 220 rpm, and then rinsed three times with 3 ml of DI water. Each tape strip was fi xed with 2.0 ml of 2.5% glutaraldehyde for 10 min. The tape strips were washed three times with 3.0 ml DI water and stained with 0.5 ml calcofl uor white for 10–15 min. The tape strips were again rinsed three times with 3.0 ml DI water and allowed to air dry. Once the tape strips were dry, the yeast cells were counted microscopically. STATISTICAL ANALYSIS OF RESULTS The yeast counts recorded using the visual release protocol were subjected to further analysis. The average and standard deviation were calculated for the triplicate counts, and t-tests were conducted to determine the statistical signifi cance of differences between the results for the different materials tested. RESULTS REMOVAL OF C. ALBICANS FROM SKIN TAPE STRIPS USING NEGATIVELY CHARGED PARTICLES Experimental results (Tables II and III, Figures 2 and 3) indicated that C. albicans was removed from skin tape strips most effectively with 3–4 μm CMC particles. PEI- Cellulose and Benonite were only marginally effective, and the other materials evaluated did not release the yeast from the skin tape strips (Table III). As demonstrated by the results in Figure 2, yeast cells were rapidly released from the skin tape strips, within the fi rst 10 min of contact with the CMC particles, as confi rmed by the visual count observations (Table II). The numbers in the table refl ect the average and standard devia- tion based on examination of three tape strips, visualizing 2 × 107 μm2 or 5% of the tape strip surface area. The ability of CMC to effectively release yeast from skin tape strips is further supported by the photomicrographs shown in Figure 4. EFFECT OF PH ON CMC EFFICACY Anionic particles were able to displace the yeast from the skin tape strips over a wide range of pH (Figure 5). Although phosphate and HEPES buffers demonstrated reduced Table II Percent Removal of Yeast from Skin Tape Strips as Measured by Visual Observation (n = 3) Material Concentration (mg/ml) Size (μm) AVG SD Percent Removal CM-Cellulose 0.4 3–4 4 2.8 97.7 PEI-Cellulose 0.4 3–4 109 12.0 36.6 DEAE-Cellulose 0.4 3–4 147 18.0 14.5