368 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table VII. Loss of chlorhexidine from mouthrinse in use Day Wt of chlorhexidine gluconate (mg) Time Given Returned Lost % Loss A. Chlorhexidine gluconate rinse Subject No. 1 1 am 5.75 4.2 1.55 27.0 pm 5.75 4.2 1.55 27.0 1 am 5.75 4.5 1.25 21.7 pm 5.75 4.3 1.45 25.2 3 am 5.75 4.0 1.75 30.4 pm 5.75 no rinse Subject No. 2 1 am 5.75 4.4 1.35 23.5 pm 5.75 5.2 0.55 9.6 2 am 5.75 4.8 0.95 16.5 pm 5.75 5.0 0.75 13.0 3 am 5.75 5.4 0.35 6.1 pm 5.75 5.05 0.70 12.2 Subject No. 3 1 am 5.75 4.1 1.65 28.7 pm 5.75 4.4 1.35 23.5 2 am 5.75 4.5 1.25 21.7 pm 5.75 4.3 1.45 25.2 3 am 5.75 4.8 0.95 16.5 pm 5.75 4.2 1.55 27.0 B. Chlorhexidine gluconate/reducing agent rinse Subject No. 4 1 am 4.9 4.2 0.7 14.3 pm 4.9 3.9 1.0 20.3 2 am 4.9 4.2 0.7 14.3 pm 4.9 4.2 0.7 14.3 3 am 4.9 4.6 0.3 6.1 pm 4.9 4.3 0.6 12.2 Subject No. 5 1 am 4.9 4.3 0.6 12.2 pm 4.9 4.5 0.4 8.2 2 am 4.9 4.4 0.5 11.4 pm 4.9 4.5 0.4 8.2 3 am 4.9 4.9 -- -- pin 4.9 4.2 0.7 14.3 Subject No. 6 I am 4.9 4.0 0.9 18.4 pm 4.9 4.0 0.9 18.4 2 am 4.9 3.9 1.0 20.4 pm 4.9 4.1 0.8 16.3 3 am 4.9 4.4 0.5 10.2 pin 4.9 4.0 0.9 18.4

DETERMINATION OF CHLORHEXIDINE IN ORAL PRODUCTS 369 Iodoch Iorobenzene, I I I I I 2 • 4 Time (min) I Figtire I. Typical P-chloroaniline calibration.