Cat.No.	Product Name	CAS	Inquiry
PE0398	Sorbitol	50-70-4	Inquiry
PE-0023	Soybean phospholipid	8002-43-5	Inquiry
PE0399	Sucrose stearate	37318-31-3	Inquiry
PE-0049	Tween 85	9005-70-3	Inquiry
PE-0048	Tween-65	9005-71-4	Inquiry
PE0396	Xylitol	87-99-0	Inquiry

Humectants are most commonly used in pharmaceutical formulations to control the moisture. Humectants, hygroscopic substances used to minimize water loss and to prevent the drying out of different types of products, are in common use not only in pharmaceuticals but also in foods, cosmetics, etc. The proper selection of a humectant in a pharmaceutical formula depends upon the dosage form, ingredients, physical and chemical characteristics, as well as stability issues.

CD Formulation provides customers with a variety of pharmaceutical excipients. Our pharmacist, scientists and researchers are committed to provide advanced products to the public. We can customize related products for customers, and also provide customers with drug development and research solutions.

Classification of Humectants Excipients

Humectants belong to surfactants, which are composed of two groups: hydrophilic group and lipophilic group. When in contact with a solid surface, the lipophilic group adheres to the solid surface, and the hydrophilic group extends outward into the liquid, so that the liquid forms a continuous phase on the solid surface, which is the basic principle of wetting. Generally speaking, wetting agents are classified according to their strength of action, route of administration, and properties.

• According to the strength of the effect: one is a solvent with low surface tension and can be mixed with water, such as ethanol, propylene glycol, glycerin, etc.; the other is a surfactant, such as anionic surfactants, certain polyol-type surfactants, Polyoxyethylene surfactant.
• According to the route of administration: According to the route of administration, wetting agents are divided into three types, one is used in external preparations, the other is used in oral preparations and injections.
• According to properties: According to properties, wetting agents are divided into anionic and nonionic surfactants.

Fig. 1 Moisturizers

Selection of Humectants Excipients

Under normal circumstances, for drugs that are not very hydrophobic, compounds such as ethanol, propylene glycol, and glycerin are usually used to grind them to achieve the purpose of wetting. For drugs or medicinal materials with strong hydrophobicity, surfactants with an HLB value between 6 and 15 are generally used. We can also choose through indicators.

Contact angle: The contact angle refers to the angle between the droplet and the spreading surface. The selected wetting agent should be able to reduce the contact angle of the hydrophobic drug to less than 90°. When the contact angle is 0, it can be completely wetted; when the contact angle is 0~90°, it can be wetted, and it is a hydrophilic drug; when the contact angle is greater than 90° but less than 180°, it cannot be wetted; when the contact angle is 180° It is completely non-wetting and is a hydrophobic drug.

Interfacial tension: Certain wetting agents alter the interfacial tension of hydrophobic drugs and solvents.

Wetting amount: the wetting point refers to the amount of solvent needed to just wet 100g of hydrophobic drugs. Adding a wetting agent can lower the wetting point, that is, reduce the amount of solvent used.

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