Determination of Particle Size Distribution of Selected Aerosol Cosmetics. II. Cascade Impactor Use in Fluorometric and Weight-by-Difference Methods

John J. Sciarra; David Adelman

872 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 50 40 30 20 ' lO ' 0 1.0 2.0 3.0 4.0 5.0 CONCENTRAT I ON-PERCENT Figure 2. Effect of concentration upon fluorescence of Blancophor AW High Concn. A. Concentration X 10 -x B. Concentration X 10 -• Table II Fluorescence of Dilute Blancophor AW High Concn. Solutions Blancophor Solution Fluorescence Readinga (wt %) (%) 0.050 72 0.045 69 0.040 64 0.035 60 0.030 57 0.025 49 0.020 39 0.015 30 0.010 19 0.005 10 0.0025 4 0 0 Primary filter, (47B q- 2A) secondary filter, (2A -- 12 q- 10% neutral filter) range, 1 X Preparation of Aerosol Samples In order to determine the effectiveness of the fluorometric method and to compare the results with the weight-by-difference method, aero- sols were prepared in a manner similar to that previously reported (5), except that a sufficient amount of Blancophor was added to produce a concentration of 0.05% by weight. The formulation consisted of 30%

PARTICLE SIZE DETERMINATION 873 by weight of concentrate and 70% by weight of Propellant 12/11* (50: 50). This was packaged in an aerosol can and fitted with an aerosol valve. The particle size distribution was determined using the Cascade Impactor and the amount of residue deposited on each slide was deter- mined by the fluorometric method of analysis. Figure 3 shows the Cas- cade Impactor disassembled with a view of the glass slides. The compari- son of these results with those previously obtained by the weight-by-differ- ence method is shown in Table III. ? Propellant 12 is dichlorodifiuoromethane and Propellant 11 is trichlorornonofiuorometh- are. Figure 3. Cascade Impactor disassembled showing glass slides Table III Comparison of Cumulative Weight Per Cent Detertnined by Different Methods Diameter Hair Spray--A Hair Spray--B of Particle Weight by Fluorotnetric Weight by Fluormnetric (u) Difference Method a Difference Methoda 1 0.44 2 1.06 4 2.24 8 3.65 16 3.87 32 4.35 Over 32 100 0 281 1 219 2 437 3 656 3 9oo 5 148 100 0.14 0.241 0.65 1.097 1.85 2.215 2.24 2.827 3.53 3.201 4.35 4.256 100 100 Average of three determinations.

Previous Page Next Page

Purchased for the exclusive use of nofirst nolast (unknown)
From: SCC Media Library & Resource Center (library.scconline.org)

Volume 22 No 13 resources

Download PDF Determination of Particle Size Distribution of Selected Aerosol Cosmetics. II. Cascade Impactor Use in Fluorometric and Weight-by-Difference Methods (11)

Extracted Text (may have errors)

872 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 50 40 30 20 ' lO ' 0 1.0 2.0 3.0 4.0 5.0 CONCENTRAT I ON-PERCENT Figure 2. Effect of concentration upon fluorescence of Blancophor AW High Concn. A. Concentration X 10 -x B. Concentration X 10 -• Table II Fluorescence of Dilute Blancophor AW High Concn. Solutions Blancophor Solution Fluorescence Readinga (wt %) (%) 0.050 72 0.045 69 0.040 64 0.035 60 0.030 57 0.025 49 0.020 39 0.015 30 0.010 19 0.005 10 0.0025 4 0 0 Primary filter, (47B q- 2A) secondary filter, (2A -- 12 q- 10% neutral filter) range, 1 X Preparation of Aerosol Samples In order to determine the effectiveness of the fluorometric method and to compare the results with the weight-by-difference method, aero- sols were prepared in a manner similar to that previously reported (5), except that a sufficient amount of Blancophor was added to produce a concentration of 0.05% by weight. The formulation consisted of 30%

PARTICLE SIZE DETERMINATION 873 by weight of concentrate and 70% by weight of Propellant 12/11* (50: 50). This was packaged in an aerosol can and fitted with an aerosol valve. The particle size distribution was determined using the Cascade Impactor and the amount of residue deposited on each slide was deter- mined by the fluorometric method of analysis. Figure 3 shows the Cas- cade Impactor disassembled with a view of the glass slides. The compari- son of these results with those previously obtained by the weight-by-differ- ence method is shown in Table III. ? Propellant 12 is dichlorodifiuoromethane and Propellant 11 is trichlorornonofiuorometh- are. Figure 3. Cascade Impactor disassembled showing glass slides Table III Comparison of Cumulative Weight Per Cent Detertnined by Different Methods Diameter Hair Spray--A Hair Spray--B of Particle Weight by Fluorotnetric Weight by Fluormnetric (u) Difference Method a Difference Methoda 1 0.44 2 1.06 4 2.24 8 3.65 16 3.87 32 4.35 Over 32 100 0 281 1 219 2 437 3 656 3 9oo 5 148 100 0.14 0.241 0.65 1.097 1.85 2.215 2.24 2.827 3.53 3.201 4.35 4.256 100 100 Average of three determinations.

Help

874 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Aerosols Containing Insoluble Material Aerosols containing a solid material of known particle size were pre- pared. Sulfadiazine Calcomites © and Microcrystals* were employed in this phase of the study and formulated as follows: Sulfadiazine Calcomites or Microcrystals Span 85* Ethanol, anhydrous Blancophor AW High Concn. Propellant 12/11 (50: 50) 0.5 10.0 20.0 0. 064 69.436 The sulfadiazine was placed in a mortar with the Blancophor and 1nixed with the Span 85. Propellant 11 was added and mixed with the powders. This slurry was then placed into an aerosol container and chilled. Pro- pellant 12 was added by the cold process and the container was then fitted with a metered valve. By means of an oral adapter, approximately 12- 15 sprays were dispensed into the sampling chamber of the Cascade Im- pactor. The results are shown in Tables IV and V and represent the average of three results of each powder. Table IV Particle Size Distribution of Sulfadiazine Calcomites Aerosol Diameter of Mass of Collected Cumulative Mass Cumulative Weight Particle (/•) Material (g) (g) Per Cent 2 0.6864 0.6864 13.61 4 1.9024 2.5888 51.70 8 2.3163 4.9051 97.95 16 0.1009 5.0060 100.00 32 ......... DISCUSSION OF RESULTS The fluorometric method of analysis has been used for many sub- stances which have the property of being fluorescent. Tracer studies have also been conducted by the addition of a fluorescent dye to a known system. Since the intensity of the fluorescent light emitted by a sample * Sulfadiazine Calcomites (American Cyanamid Corp., N.Y.), 99% of the particles are less than 10tz and 95% are less than 4tz. Microcrystals, 99.7% of the particles less than 10tz and 50% less than 5tz. • Sorbitan Sesquioleate, Atlas Chemical Industries, Wilmington, Del.

PARTICLE SIZE DETERMINATION Table V Particle Size Distribution of Sulfadiazine Microcrystals Aerosol 875 Diameter of Mass of Collected Cumulative Mass Cumulative Weight Particle (u) Material (g) (g) Per Cent 1 0.3803 0.3803 11.87 2 1.0309 2.0612 44.66 4 1.5309 3.5427 75.45 8 1.3127 4.8553 100.00 16 ......... 32 ......... under constant input light intensity is directly proportional to the con- centration of the fluorescent comp,ound, these substances can be used as tracers (6). The use of one such fluorescent compound for this purpose has been shown in this paper. As can be seen in Fig. 2, the initial con- centration of the material must be carefully selected so that in the range of concentration used, fluorescence becomes indicative of concentration. Concentrations of Blancophor above 0.05% were noted to produce only slight increase in fluorescence with an increase in concentration. For this reason, 0.05% was the maximum concentration of Blancophor used in this study. Two hair spray aerosols, having a different particle size distribution, were studied by both the weight-by-difference and fluorometric methods of analysis. Table III gives a comparison of the results. It can be noted that the particle size distribution as determined by the fluorometric method tends to give slightly higher cumulative weight per cent than that given by the other method. This could possibly be due to the greater ac- curacy of fluorometric analysis. To convert per cent fluorescence to cumulative weight per cent, the assumption was made that if a 5-ml sample could be recovered from the aerosol product and its fluorescence determined, the reading would be 72% (as shown in Table II and Fig. 2). By adding a sufficient amount of dye to the aerosol to produce a 0.05% by weight solution, this assumption becomes valid. The amount of dye deposited on each slide is then equal to Known concn. o[ dye in sample X fluorescence o[ slide Fluorescence of sample or 0.05 x fluorescence o[ slide 72

Previous Page Next Page

Purchased for the exclusive use of nofirst nolast (unknown)
From: SCC Media Library & Resource Center (library.scconline.org)

Volume 22 No 13 resources

Download PDF Determination of Particle Size Distribution of Selected Aerosol Cosmetics. II. Cascade Impactor Use in Fluorometric and Weight-by-Difference Methods (11)

870 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Figure 1. Assembled Cascade Impactor fitted with sampling chamber Fluorometric Method A fluorometric method was also used to determine quantitatively the amount of residue deposited on each slide. A Turner Fluorometer,* Model 111, was fitted with the proper primary and secondary filters, de- pending upon the nature of the fluorescent dye used as a tracer. Each of the slides from the Cascade Impactor was thoroughly washed with 5 ml of anhydrous ethanol in a 10-ml beaker in order to dissolve the residue. The sample was then transferred to a 5-ml Pyrex glass cuvette and its per cent fluorescence determined. This method was used throughout this study. Selection o[ Tracer Dye Several different fluorescent compounds were investigated. Prelim- inary studies indicated that Blancophor AW High Concn.* might be use- ful for this purpose. Chemically, this compound is 4-methyl-7-dimethyl aminocoumarin. * G. K. Turner Associates, Inc., Palo Alto, Calif. • GAF Corporation, Dyestuff and Chemical Division, New York.

PARTICLE SIZE DETERMINATION 871 OH3 CH3-- N••H:••0 Peak absorption occurs at approximately g66 m/• (long-wave UV range) while peak readmission o[ visible light occurs at between 465 and 470 m/x although there may be some variation depending' upon the sub- strate. Solutions of Blancophor were prepared in absolute ethanol.* A solution containing 0.50% by weight o[ Blancophor was diluted with ab- solute ethanol in order to produce concentrations in the range o[ 0 to 0.5% by weight. The fiuorometer was fitted with the filter combination shown in Table I. Five milliliters of each dilution was placed in a cu- vette and the per cent fluorescence was read. These results are shown in Table I and Fig. 2 and represent the average o[ three determinations. The above procedure was repeated using dilutions o[ Blancophor in the range o[ 0 to 0.05% by weight of solution using absolute ethanol as the solvent. These results are shown in Table II and Fig'. 2 and repre- sent the average o[ three determinations. * Similar dilutions were prepared using SDA 40 anhyd. and no change in fluorescence was noted using the filter combinations indicated. Table I Fluorescence of Blancophor AW High Concn. Solutions Blancophor Solution Fluorescence Readinga (wt %) (%) 0.50 76 0.45 75 0.40 74 0.35 70 0.30 68 O.25 65 0.20 61 0.15 54 0.10 47 0.05 36 0. 025 24 0.0125 15 0. 0063 12 0.0031 7 0.0016 4 0 0 ', Primary filter, (47B q- 2A) secondary filter, (2A -- 12 or 15 -b 1% neutral filter) range, 10X.

Previous Page Next Page

Purchased for the exclusive use of nofirst nolast (unknown)
From: SCC Media Library & Resource Center (library.scconline.org)

Volume 22 No 13 resources

Download PDF Determination of Particle Size Distribution of Selected Aerosol Cosmetics. II. Cascade Impactor Use in Fluorometric and Weight-by-Difference Methods (11)

Volume 22 No 13 resources

All section downloads (PDF) click to expand contents

Extracted Text (may have errors)

Help

loading

Volume 22 No 13 resources

Volume 22 No 13 resources