Analytical chemistry of dimethicones in personal care creme formulations

1. Polydimethylsiloxane Determination in Lotionized Formulations Using Quantitative FTIR Part 1: Linearity Studies Luke Shokere, Ph.D.

5. Table 1. Sample preparation. 1.80 3928 72 120 1.65 3934 66 110 1.50 3940 60 100 1.35 3946 54 90 1.20 3952 48 80 0 4000 0 0 Dimethicone Placebo Dimethicone Sx wt. % wt. mg mg % Normal

6. Figure 1a. FTIR spectral results for the 1260cm -1 peak. Blue 120%; Red 110%; Black 100%; Brown 90%; Green 80%; Black, Placebo (no peak).

7. Figure 1b . Method of peak integration at 1260cm-1 . The signature peak that corresponds to the H 3 C-Si bond vibration (stretching action) is integrated. Smaller peak on right shoulder is the H 3 C bond vibration of the Hexane solvent.

8. Figure 2. Linearity plot.

9. Table 2. Peak integration absorbance results 0.1922 120 0.1706 110 0.1516 100 0.1302 90 0.1077 80 0.0000 0.0 Absorbance Dimethicone FTIR % Normal