Foodstuff and Pharmaceuticals

Surfactants can be used in the food industry as emulsifiers, solubilizers, stabilizers, etc. (food-grade), to improve food texture, taste, and preservability.

Emulsifiers: Added to products such as margarine, ice cream, milk drinks, baked goods, and chocolate. They can stabilize oil-water systems, prevent stratification or precipitation, build structures, ensure that finished products and ingredients maintain emulsions during transportation and storage, thereby improving product quality, extending product shelf life, altering crystallization, preventing adhesion, and retaining moisture. Common types: mono/diglycerides (GMS, DMG), lecithin, sucrose esters, polyglycerol fatty acid esters.

Thickeners: Used as food thickeners, widely applied to change rheological and textural properties, and improve quality attributes without affecting other characteristics such as taste. The main functions of food thickeners are to enhance water-binding capacity, as well as modify structure and change flow behavior characteristics.

Foaming agents/Defoamers: Used in beer, cream (foaming), fermentation tanks, fruit juice drinks (defoaming). Some foods require foam (cream, candies), while others need rapid defoaming (beverages, fermentation tanks). Common types: Foaming agents: proteins, saponins, and synergistic emulsifiers; Defoamers: polydimethylsiloxane (food-grade silicone oil), polyethers.

Solubilizers/Dispersants: Used in beverage emulsified flavors and functional beverage vitamin addition, to disperse lipophilic substances such as flavors, pigments, and vitamin oils in the aqueous phase. Common types: Tween series, sucrose esters, polyglycerol esters.

Stabilizers/Anti-crystallization agents: Used in ice cream (to prevent coarsening of ice crystals in frozen foods), chocolate (to prevent oil precipitation), salad dressings (to prevent oil/water emulsion separation), jams and yogurts (to prevent water release from fruits). They stabilize dispersion systems and preserve product structure. Common types: glycerol fatty acid esters, sucrose esters, lactate esters.

Anti-caking agents/Wetting agents: Used in milk powder, coffee creamer, and cocoa powder. They improve powder fluidity, prevent caking; help instant powders quickly wet and dissolve. Common types: silicon dioxide (physical additive), small amounts of emulsifiers (lecithin).

In the medical field, surfactants can be utilized for drug solubilization, dispersion, controlled release and disinfection (for medicinal purposes), thereby enhancing the efficacy of the drugs and the stability of the formulations.

Solubilizers/Emulsifiers: Used in injections, oral solutions, and ointments. They dissolve poorly soluble drugs (lipophilic vitamins, steroids, antibiotics) to form transparent solutions or emulsions. Common types: polysorbates (Tween), PEG fatty acid esters, lecithin, polyoxyethylene hydrogenated castor oil (Cremophor EL). For drugs with poor water solubility, the use of surfactants is inevitable to reduce the interfacial tension between the medium and the drug and improve drug solubility.

Wetting Agents/Dispersants: Used in solid preparations (tablets, capsules) and inhalation preparations. They improve the wettability of poorly soluble drug particles and promote uniform dispersion. Common types: SLS (sodium lauryl sulfate, with pharmacopoeial limits), poloxamers (Poloxamer, EO/PO block copolymers).

Suspending Agents/Stabilizers: Used in oral suspensions and external lotions. They prevent sedimentation of suspensions and maintain uniformity. Common types: colloidal silicon dioxide, polyvinylpyrrolidone (PVP, commonly used though not a typical surfactant), some non-ionic surfactants.

Preservatives/Antimicrobial Agents: Used in eye drops, nasal sprays, and skin disinfectants. Some cationic surfactants have antimicrobial effects and can be used as preservatives/excipients. Common types: benzalkonium chloride (BKC), benzalkonium bromide.

Controlled Release/Drug Delivery Functions: Used in anticancer drug carriers and vaccine adjuvants (such as liposomal mRNA vaccines).