Povidone or Polyvinylpyrrolidone or PVP is a water-soluble synthetic polymer widely used in cosmetics, pharmaceuticals, and personal care products. It is valued for its film-forming, binding, and solubilizing properties, making it a versatile ingredient in products such as mouthwashes, shampoos, lotions, and pharmaceutical products like tablets and gels. In cosmetics, Povidone forms a protective film that helps retain moisture, improving skin texture and enhancing hair manageability.
Chemical Composition and Structure
Povidone is a polymer formed by the polymerization of vinylpyrrolidone monomers. Its chemical formula varies depending on the molecular weight, but its basic structure consists of linear chains of repeating vinylpyrrolidone units. Its water solubility and film-forming ability make it ideal for a wide range of cosmetic and pharmaceutical applications.
Physical Properties
Povidone typically appears as a white or yellowish powder, highly soluble in water and many organic solvents. It can vary in viscosity and molecular weight depending on the needs of the final product. In cosmetics, it creates a thin, invisible film that acts as a protective barrier and conditioning agent.
The name defines the structure of the molecule:
- "Poly" is a prefix used in chemistry to indicate that a substance is a polymer, a large molecule composed of repeated subunits.
- "Vinyl" refers to the presence of a vinyl group in the monomer, a type of functional group with the formula CH = CH2. In the case of N-vinylpyrrolidone, the vinyl group is attached to the nitrogen atom.
- "Pyrrolidone" refers to the pyrrolidone ring, a five-member ring structure with the formula C4H7NO. In N-vinylpyrrolidone, the nitrogen atom in the ring is bound to the vinyl group.
The synthesis process takes place in several stages:
- Step 1: Preparation of the raw material: N-vinylpyrrolidone (NVP), a type of vinyl monomer.
- Step 2: Polymerization. NVP undergoes a polymerization reaction, in which several NVP molecules react together to form long chains. This reaction begins with the addition of a suitable initiator, which starts the polymerization process.
- Step 3: Purification. The resulting polyvinylpyrrolidone is then purified to remove any unreacted NVPs and other impurities with a series of washing and filtration steps.
- Step 4: Drying. The purified polyvinylpyrrolidone is then dried to remove any residual solvent.
It occurs in the form of a fine white powder or crystalline granules.
What it is used for and where
Food
Labelled with the number E1201 in the list of European food additives with function as a thickening agent.
Medical
In configuration Povidone-Iodine is called Topical Iodine and serves as an antiseptic as it releases iodine. It is also used in surgery to prevent infection from surgical incisions.
In Otorhinolaryngology it is used for nasal ointments (1).
It is used in ophthalmology to treat various infections including conjunctivitis (2) and to reduce contamination of the surgical site during eye surgery (3).
In dentistry, disinfectant solutions are prepared to combat periodontitis and other infections (4).
Pharmaceutical
In the pharmaceutical industry it is an excipient with the function of dispersing and suspending the release of the drug, it is also a binder for tablets, flow assistant for the capsule, stabiliser for the enzyme and the active ingredients of heat-sensitive drugs, co-precipitant for poorly soluble substances.
Cosmetics
Shampoo foam stabiliser, liquid stereotyping agent, dispersant and hair dye agent. Non-irritating humectant, viscosifying and lubricating agent. Used in deodorants, sunscreen and toothpastes.
INCI functions:
Antistatic agent. Static electricity build-up has a direct influence on products and causes electrostatic adsorption. The antistatic ingredient reduces static build-up and surface resistivity on the surface of the skin and hair.
Binder agent. Ingredient that is used in cosmetic, food and pharmaceutical products as an anti-caking agent with the function of making the product in which it is incorporated silky, compact and homogenous. The binder, either natural such as mucilage, gums and starches or chemical, may be in the form of a powder or liquid.
Emulsion stabilizer. Emulsions are thermodynamically unstable. Emulsion stabilisers improve the formation and stability of single and double emulsions. It should be noted that in the structure-function relationship, molar mass plays an important role.
Film-forming agent. It produces, upon application, a very thin continuous film with an optimal balance of cohesion, adhesion and stickiness on skin, hair or nails to counteract or limit damage from external phenomena such as chemicals, UV rays and pollution.
Hair fixative. This ingredient has the ability to create, with its protective film, stiffness and hold in the hair, and also has the ability to form, with its hydrophilic and elastic properties, bonds between the hair fibres, to keep the hair in a particular shape for a certain time.
Viscosity control agent. It controls and adapts viscosity to the required level for optimal chemical and physical stability of the product and dosage in gels, suspensions, emulsions, solutions.
Medical Applications
Pharmaceuticals. Povidone is often used as an excipient in tablets and capsules. It can also act as a solubilizing agent to enhance the solubility of drugs.
Antiseptic. A form of povidone, called Povidone-Iodine, is a popular disinfectant used for skin cleansing prior to surgeries and for wound treatment.
Ophthalmology. It might be present in some ophthalmic solutions.
Commercial Applications
Cosmetics and Personal Care Products. Povidone is used as a binding and film-forming agent in various cosmetic products.
Industry. It's used as an adhesive and dispersing agent across various industries.
Animal Health Products. It can be utilized in veterinary formulations.
The most relevant studies on the subject have been selected with a summary of their contents:
| Appearance | White crystal powder |
| Boiling Point | 217.6ºC at 760 mmHg 90-93°C |
| Melting Point | 300°C |
| Flash Point | 93.9°C |
| Density | 1.44-1.69g/cm3 1.147 ~ 1.268 g/ml |
| PSA | 20.31000 |
| LogP | 0.69020 |
| Water Solubility | 100mg/mL |
| Storage | 2-8°C |
| Safety |  |
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- Molecular Formula C6H9NO (C6H9NO)n
- Molecular Weight 111.144 g/mol
- CAS: 9003-39-8 88-12-0 25249-54-1
- EC Number: 1312995-182-4
- UNII: 76H9G81541
- DSSTox Substance ID DTXSID2021440 DTXSID0025941
- IUPAC 1-ethenylpyrrolidin-2-one
- InChI=1S/C6H9NO/c1-2-7-5-3-4-6(7)8/h2H,1,3-5H2
- InChl Key WHNWPMSKXPGLAX-UHFFFAOYSA-N
- SMILES C=CN1CCCC1=O
- PubChem Substance ID: 24899317
- MDL number: MFCD00149016
- ChEBI 82551
- ICSC 1478
- NSC 683040 142693 114022 10222
- RTECS UY6107000
Synonyms:
- PVP K120
- PVP K30
- N-Vinylpyrrolidone
- Povidone K30
- 1-Vinyl-2-pyrrolidone
- N-Vinylpyrrolidinone
- 1-Vinylpyrrolidone
- N-Vinyl pyrrolidone
- Vinylpyrrolidone
