Hydroxypropyl methylcellulose (HPMC) is a widely used polymer compound with a variety of applications in medicine, food, cosmetics and construction. The question of the hydrophilicity and lipophilicity of HPMC mainly depends on its chemical structure and molecular properties.

Chemical structure and properties of HPMC
HPMC is a non-ionic cellulose derivative formed by introducing hydroxypropyl and methyl groups into the cellulose molecular structure. Its molecular chain contains hydrophilic hydroxyl (-OH) and lipophilic methyl (-CH3) and hydroxypropyl (-CH2CH(OH)CH3) groups. Therefore, it has two affinities, both hydrophilic and lipophilic, but the hydrophilicity is slightly dominant. This property gives it good solubility, film-forming and thickening properties, and can form stable colloidal dispersions in aqueous solutions and organic solvents.

Hydrophilicity of HPMC
Due to the large number of hydroxyl groups in the HPMC structure, its molecular chain has a strong hydrophilicity. In water, HPMC can form hydrogen bonds, allowing the molecules to dissolve in water and form a high-viscosity solution. In addition, HPMC also has excellent water retention and is widely used as a thickener and stabilizer in medicine, food and cosmetics. For example, HPMC can be used as a sustained-release agent in pharmaceutical preparations to delay the release rate of drugs in the body and improve the stability of drug efficacy.

Lipophilicity of HPMC
The methyl and hydroxypropyl groups in the HPMC molecule have certain hydrophobicity, so HPMC also has certain lipophilicity, especially in low polarity or organic solvents to form a stable solution. Its lipophilicity enables it to mix with some oil phase substances, which enhances the application potential of HPMC in oil-in-water (O/W) emulsions and latexes. In some emulsions or compound preparations, the lipophilicity of HPMC helps to form a uniformly dispersed system with hydrophobic substances, thereby optimizing the distribution and stability of the ingredients.

Application of HPMC
Pharmaceutical preparations: HPMC is often used as a sustained-release coating material in tablets, using its hydrophilicity and film-forming properties to control the drug release rate.
Food industry: In food, HPMC is used as a thickener and water retainer to extend the shelf life of food and improve the taste.
Building materials: HPMC’s water solubility and thickening effect make it a cement mortar thickener in construction, improving the workability and water holding capacity of the material.
Cosmetics: In skin care products, HPMC can be used as an emulsifier stabilizer. Due to its hydrophilicity, it can form an aqueous matrix to maintain the moisturizing effect and texture of the product.
HPMC is an amphiphilic polymer material that is both hydrophilic and lipophilic, but because it has more hydroxyl groups, it exhibits a stronger hydrophilicity.