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Silicones in Cosmetics
Published in E. Desmond Goddard, James V. Gruber, Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
E. Desmond Goddard, James V. Gruber
While there are many types of silicone polymers to choose from when formulating personal care products, the most commonly utilized are PDMS. This class of unmodified silicones comprise approximately of all silicone compounds found in personal care formulations, and include materials under the INCI designations of cyclomethicone, hexamethyl disiloxane, dimethicone, and dimethiconol. PDMS polymers can exist in linear structures with a degree of polymerization ranging from zero (hexamethyl disiloxane) to several thousand. Dimethylsiloxane compounds may also exist in the form of cyclic ring structures known as cyclomethicone. Currently, the term “cyclomethicone” is used to refer to all the cyclic dimethylsiloxane compounds employed in personal care formulations; however, there is an expressed desire to specify the individual materials as cyclotrisiloxane, cyclotetrasiloxane, cyclopentasiloxane, and so forth (17). Of the cyclic dimethyl fluids, ring sizes of four (referred to as octamethylcyclotetrasiloxane, , or tetramer), five (referred to as decamethylcyclopentasiloxane, , or pentamer), and six (dodecamethylcyclohexasiloxane, , or hexamer) are most frequently encountered in cosmetic products, but rings containing from three to 10 or more silicone atoms are known to exist.
A mechanistic evaluation of the potential for octamethylcyclotetrasiloxane to produce effects via endocrine modes of action
Published in Critical Reviews in Toxicology, 2021
Because of its presence at low levels in consumer products and the biosphere, several studies in animals, cells in culture, and isolated receptors have examined the biological fate and effects of D4. The focus of this review is to catalogue those actions of D4 for which there is a hypothesis of a potential endocrine system-related mode of action and to determine the potential of these actions for producing adverse effects. The information in this review encompasses all of the available data, from the earliest report in 1988 to the present, on the potential endocrine system-related actions of D4. Most of the data for D4 and decamethylcyclopentasiloxane (D5) are from unpublished research reports from the Dow Corning Corporation (DCC). Some of this data has also been published. The author relied primarily on the original data for the preparation of this review. Most of the in vivo studies have employed the rat as the experimental subject. D4, only at high doses (e.g. ≥300 ppm for inhalational exposures), produces a variety of effects on female reproductive parameters. The possibility that any of these effects on the female reproductive system may be due to an endocrine mode of action is evaluated according to the weight of evidence, tier 1 guidelines of the United States Environmental Protection Agency endocrine disruptor screening program (U.S. EPA 2011) and the evidence for each potential endocrine system effect is prioritized consistent with the hypothesis-driven framework and endpoint rankings as described by Borgert et al. (2011, 2014), de Peyster and Mihaich (2014), Mihaich et al. (2017), Neal et al. (2017), and Mihaich and Borgert (2018).
Research on the relationship between cephalosporin structure, solution clarity, and rubber closure compatibility using volatile components profile of butyl rubber closures
Published in Drug Development and Industrial Pharmacy, 2019
Xiao-Meng Chong, Xin Dong, Shang-Chen Yao, Chang-Qin Hu
The commercially available reference substances of volatile components, namely carbon disulfide (CS2), trimethylsilanol, cyclohexane, 1,1-Dimethylsilanediol, hexamethylcyclotrisiloxane, ethylbenzene, m-Xylene, 1,2-dimethylbenzene, octamethyl cyclotetrasiloxane, decamethylcyclopentasiloxane, 2,5-Di-tert-butyl-1,4-benzoquinone, and BHT were obtained from Sigma-Aldrich (St. Louis, MO).