Dimethicone

CAS NO.：9006-65-9

Purity: 97.0%‑103.0%
Appearance: Colorless, clear, oily liquid, odorless and tasteless

Product name	Dimethicone
Product Categories	silicone oil;UVCBs-polymer;Miscellaneous Reagents;9006-65-9
CAS NO.	9006-65-9
MF	C6H18OSi2
MW	162.37752
Density	1 g/mL at 20 °C
Structural formula
Product Manager Email	Nicole@coreychem.com

Frequently Asked Questions

Question 1: What is Dimethicone?

Dimethicone is polydimethylsiloxane, CAS No. 9006‑65‑9, monographed in Volume IV of the Chinese Pharmacopoeia and classified as a pharmaceutical excipient (defoaming agent, lubricant). It is a clear, colorless oily liquid, odorless and tasteless.

In terms of solubility, it is practically insoluble in water and ethanol, and freely soluble in non-polar solvents such as chloroform and toluene.

Question 2: How many viscosity grades are there, and how do they correspond to uses?

Viscosity reflects the polymer chain length (degree of polymerization) and is the most critical quality attribute and selection criterion for Dimethicone. The pharmacopoeia specifies 10 viscosity grades based on kinematic viscosity at 25℃ (mm²/s, cSt): 20, 50, 100, 200, 350, 500, 750, 1000, 12500, and 30000, grouped into three application bands: low viscosity 20–500 for creams, aerosols, defoaming, and lubrication; medium viscosity 750–1000 for oral emulsions and process defoaming; high viscosity ≥12500 for ophthalmic ointments and suppository bases.

Question 3: Is pharmaceutical-excipient Dimethicone the same as medicinal Dimethicone?

Identity distinction: they are not the same. As a pharmaceutical excipient, Dimethicone is a raw material for formulation manufacturing, serving only the process and the dosage form. When Dimethicone is used as the active ingredient in dimethicone tablets, powders, or emulsions for therapeutic purposes (e.g., gastrointestinal defoaming), it is a medicinal product governed by drug standards and no longer an excipient.

Two identities, two sets of standards—they must not be conflated.

Question 4: How safe is it?

First, it is virtually not absorbed via the gastrointestinal tract or through the skin, hardly enters the bloodstream, and is excreted unchanged, resulting in extremely low systemic toxicity—suitable for both oral and topical use.

Second, the pharmaceutical grade must comply with all pharmacopoeial impurity limits (heavy metals, arsenic, mineral oil, etc.).

Third, an excipient-grade material used in formulations must complete CDE (Center for Drug Evaluation) drug excipient registration, with a COA and impurity documentation, before it can be used in drug application and production.

Question 5: How should it be stored?

Storage: Keep in tightly closed containers, stored in a cool, dry place away from high temperature and contamination. Different viscosity grades should be stored separately with clear labeling to prevent mix-ups, and pharmaceutical-grade material must be strictly segregated from industrial-grade silicone oil.

Application 1 — Dimethicone is a defoaming agent for oral and topical processes.

Oral preparations—defoaming during fermentation and extraction processes, and eliminating foam in the manufacture of suspensions and emulsions (as an excipient, it performs process defoaming only; when used in gastrointestinal preparations for therapeutic defoaming, it acts in the capacity of an active ingredient). Topical preparations—defoaming during the production of creams and gels, reducing bubble defects in finished products and ensuring appearance and homogeneity.

Application 2 — Dimethicone serves as a lubricant and mold-release agent across multiple dosage forms

It is primarily used for demolding of suppositories and drop pills, allowing formed preparations to release cleanly; for anti-sticking in tablet compression, preventing punch adhesion; and in film coating, where it improves spreading and provides moisture protection.

Application 3 — Dimethicone functions as a topical base and skin-protective film former

It serves as a base component of ointments and creams, markedly improving spreadability and skin feel (smooth and non-greasy), and forms a hydrophobic protective film on the skin surface, providing isolation and moisture protection. It is used in topical and transdermal preparations. For patients, this translates to a comfortable application with an added sense of protection.

Application 4 — Dimethicone also provides process lubrication beyond the formulation itself.

It lubricates medical-device tubing and supports auxiliary roles such as anti-sticking throughout manufacturing.

Application 5 — Besides the formulations themselves, what other process uses does it have?

Lubrication of medical-device tubing—as an excipient application, it gives catheters and tubing interiors a smooth surface, facilitating intubation and use. In addition, across the production lines of the dosage forms mentioned above, it simultaneously performs auxiliary roles such as process lubrication and anti-sticking, making it a versatile player throughout compounding, forming, coating, and filling operations.

Packaging:

1 kg/bottle
25 kg/drum
200 kg/drum
Other pack sizes available on request

Product actual photos：