658 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Antiperspirant Fornmlation Concentrate Per Cent by Weight l. lsopropyl myristate" 55.45 2. Cab-O-Sil M-5 b 3.64 3. Aluminumchlorhydrate a 31.82 4. Q-CAP perfumec 9.09 Fill Concentrate 11.00 Propellants (50: 50) 11/12 89.00 Wickhen Products, Inc., Huguenot, N.Y. Cabot Corporation, Boston, Mass. Registered trademark of Polak's Frutal Works, Inc., Middletown, N.Y. Figure 2. Sampling device and syringe Control samples were also prepared using corresponding unencapsu- lated.liquid materials in the same formulation. Depending upon the spe- cific vapor pressure of the material involved, a variety of dosages were

ENCAPSULATED PERFUMES 659 .' :. -:• ß .• :•v*•- ....... :'•' • :: .: ... , - •... ..., . 'i . Figure 3. In vitro sampling apparatus .'½ . ... .. :..... used in the finished aerosol samples. (These dosages ranged from 0.4 to 1.0% for the encapsulation with an equivalent range of 0.2 to 0.5% for the unencapsulated oil.) Aerosol samples, prepared as previously de- scribed, were applied to either silicone rubber pads, for in vitro tests, or to the axillary region of a human subject, for in vivo tests. A sampling device was developed to entrap the perfume vapors above the axillary region consisting of a copper cylinder, 11/2 in. in diameter and 3 in. long, with a silicone septum at the closed end, and having a volume of 100 cc (Fig. 2). In practice, the open end of the cylinder is placed over the tested region for 60 sec, as shown in Fig. 3, and then a vapor sample is withdrawn into a 10-cc gas-tight hypodermic syringe equipped with a 3-in., No. 22 needle, also shown in Fig. 2. A 3-ft, 1/4-in. o.d. copper column filled with 2.0% Apiezion M* on 60 * Apiezion M is available from Jamcs G. Biddle Co., Plymouth Meeting, Pa.