Product Introduce

Polyoxyl 35 castor oil also known as PEG-35 Castor Oil,is a nonionic surfactant that appears as a pale yellow, viscous liquid at room temperature. It solidifies into a paste at low temperatures. This product is highly soluble in water and soluble in fats, mineral oils, waxes, fatty acids, and various organic solvents. In a 1% aqueous solution, its pH ranges from 6 to 8. It is resistant to acids, hard water, and inorganic salts. It is alkali-resistant at low temperatures, but strong alkalis can cause it to hydrolyze. It is primarily used as an emulsifier in pesticides and as a dispersant in printing pastes. It can also be used to formulate antistatic spinning oils for acrylic and vinylon fibers. Polyoxyl castor oil is obtained by the condensation of castor oil with ethylene oxide.

Products Specifications

Test Item	Executive Standard	Test Result
Description	A white,off-white,or pale yellow paste or viscous liquid;slightly odorous.this product is readily soluble in ethanol.	A pale yellow,viscous liquid;slightly odorous.This product is readily soluble in ethanol.
Relative Density(25℃)	1.05~1.06	1.05
Viscosity 25℃(mm²/s)	570-710	674
Acid Value	Max.2.0	0.5
Saponification Value	65~70	68
Hydroxyl Value	65~78	70
Lodine Value	25~35	32
Identification	Upon the dropwise addition of bromine solution,the color of the bromine immediately fades.	Exhibit a correct response
Identification	The infrared absorption spectrum of this product should be consistent with that of the Polyoxyethylene Castor Oi Reference Standard.	Consistent
Examine
acidity	5.0~7.0	6.2
Clarity and Color of the Solution	The solution shall be clear and colorless;if turbid,it shall not be more turbid than Turbidity Standard Solution No.3;if colored,it shall not be darker than Orange Yellow Color Standard Solution No.1.	Conforms
Ethylene Glycol and Diethylene Glycol	Ethylene glycol shall not exceed 0.062%.	0.0072%
	The sum of ethylene glycol and diethylene glycol shall not exceed 0.25%	0.031%
Ethylene Oxide and 1,4-Dioxane	Ethylene oxide shall not exceed 0.0001%.	ND
	1,4-Dioxane shall not exceed 0.001%.	ND
Moisture	Not more than 0.5%	0.4%
Residue on Ignition	Not more than 0.2%	0.03%
Heavy Metals	Not more than 10 ppm	Conforms
Arsenic Salts	Must comply with regulations(not more than 2 ppm)	Conforms
Bacterial Endotoxins	The endotoxin content per 1 mg of sample must not exceed 0.012 EU	Conforms
Microbial Limits	Per 1g of test specimen,the total aerobic bacterial count must not exceed 10² CFU,the total mold and yeast count must not exceed 10² CFU,bile tolerant Gram negative bacteria must not be detected,and Escherichia coli,Staphylococcus aureus,and Pseudomonas aeruginosa must not be detected;Salmonella must not be detected per 10 g.	<10 CFU/g,<10 CFU/g,ND

Made from refined castor oil, with a light color and low impurity content;

Narrow molecular distribution, resulting in good batch-to-batch stability;

Low impurity content, low allergenicity, and low hemolytic activity, ensuring product safety;

Controlled bacterial endotoxins and microbial limits, suitable for injectable applications.

FAQ

Q: What Is Polyoxyl 35 Castor Oil Used for in Pharmaceutical Formulations?

A: Polyoxyl 35 Castor Oil is a nonionic pharmaceutical excipient widely used as a solubilizer and emulsifier in oral, topical, and liquid pharmaceutical formulations. It helps improve the solubility of poorly water-soluble active pharmaceutical ingredients (APIs), enhances formulation stability, and supports the development of clear and homogeneous dosage forms.

Q: Is Polyoxyl 35 Castor Oil a Pharmaceutical Excipient?

A: Yes. Pharmaceutical-grade Polyoxyl 35 Castor Oil is widely used as a pharmaceutical excipient because of its excellent solubilizing and emulsifying properties. Products complying with USP, EP, and ChP specifications are suitable for pharmaceutical manufacturing and quality-controlled formulations intended for regulated markets.

Q: Why Is Polyoxyl 35 Castor Oil Used as a Solubilizer?

A: Polyoxyl 35 Castor Oil is particularly effective at increasing the solubility of hydrophobic active ingredients, essential oils, and other poorly water-soluble substances. By improving dispersion and maintaining formulation clarity, it helps enhance product stability and manufacturing consistency.

Q: What Dosage Forms Commonly Use Polyoxyl 35 Castor Oil?

A: Polyoxyl 35 Castor Oil is commonly used in oral liquids, topical preparations, ophthalmic formulations, and other pharmaceutical dosage forms that require efficient solubilization or emulsification. It is also used in cosmetic and personal care formulations where clear solutions and stable emulsions are required.

Q: What Is the Difference Between Polyoxyl 35 Castor Oil and Polyoxyl 40 Hydrogenated Castor Oil?

A: Although both are nonionic surfactants used as solubilizers, they differ in raw materials, manufacturing processes, and formulation performance. Polyoxyl 35 Castor Oil is produced from castor oil, while Polyoxyl 40 Hydrogenated Castor Oil is derived from hydrogenated castor oil. The choice depends on the desired solubilization efficiency, compatibility, and formulation requirements.

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