E1201 (Polyvinylpyrrolidone or PVP) better known as Povidone,  is a water-soluble polymer consisting of N-vinylpyrrolidone. 

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 appears in the form of a fine, white powder.

What it is used for and where

It is a very versatile component. In 1930, PVP patent was filed as one of the most interesting chemicals of acetylene chemistry and has been used to replace blood plasma and subsequently in a variety of applications in medicine, pharmacy, cosmetics (1).

Food

Ingredient included in the list of European food additives as E1201 with anti-caking and emulsifying function.

Cosmetics

• 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 a continuous ultra-thin film with an optimal balance of cohesion, adhesion and stickiness on the skin or hair 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

It has a high expansion capacity and acts as an emulsifier. It serves to enhance and accelerate the release of the drug in medicinal tablets.

It is also used as adhesive, emulsion stabilizer, suspension agent and hair styling agent in cosmetics and beauty products, mainly in mascara, eyeliner, hair conditioner, hairspray, shampoo and other hair care products. Clarifying agent, thickening agent, stabilizing agent and dispersing agent.

Together with croscarmellose sodium, sodium glycolate starch and others it is considered a super disintegrant (2).

This study examined the extent and direction of tablet size expansion during disintegration caused by various disintegrants including crospovidone (3).

The most relevant studies on the subject have been selected with a summary of their contents:

Polyvinylpyrrolidone studies

Typical optimal characteristics of the commercial product Polyvinylpyrrolidone

• Molecular Formula: C₆H₉NO  (C₆H₉NO)n
• Molecular Weight: 111.144 g/mol
• UNII: 76H9G81541
• CAS:  9003-39-8         
• EC Number: 1312995-182-4         
• PubChem Substance ID 24899318
• MDL number MFCD00149016
• Beilstein Registry Number 110513
• DSSTox Substance ID: DTXSID2021440     DTXSID0025941
• 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
• IUPAC 1-ethenylpyrrolidin-2-one
• ChEBI  82551

Synonyms:

• N-Vinyl-2-Pyrrolidone
• N-Vinylpyrrolidone
• 1-Vinyl-2-pyrrolidone
• 1-vinylpyrrolidin-2-one
• N-Vinyl-2-pyrrolidinone
• Vinylpyrrolidone
• 1-Vinylpyrrolidone
• Plasdone
• Povidone
• eriston
• Polyvidone
• Protagent
• Bolinan
• 1-Vinylpyrrolidinone
• Vinyl-2-pyrrolidone
• Polyplasdone XL
• Polyclar AT
• V-Pyrol
• Neocompensan
• Poly-N-vinyl pyrrolidone
• Vinylpyrrolidinone polymer
• Poly(N-vinylbutyrolactam)
• N-Vinylpyrrolidone polymer
• Poly(N-vinylpyrrolidinone)
• N-Vinylbutyrolactam polymer
• Poly(1-vinylpyrrolidinone)
• N-Vinylpyrrolidinone polymer
• Polyvinylpyrrolidine
• Poly(N-vinyl-2-pyrrolidone)
• PVP K 3
• N-Vinyl-2-pyrrolidone polymer
• 1-Vinyl-2-pyrrolidone polymer
• MPK 90
• Poly(N-vinyl-2-pyrrolidinone)
• PVP-K 30
• PVP-K 60
• PVP-K 90
• Vinylbutyrolactam
• Vinylpyrrolidinone
• 1-ethenylpyrrolidin-2-one
• PVP 1
• PVP 2
• PVP 3
• PVP 4
• PVP 5
• PVP 6
• PVP 7
• 1-Vinyl-2-pyrrolidinone
• Polyvinylpyrrolidone

References_________________________________________________

(1) Sanner AHF, Straub F. Polymers of N-vinylpyrrolidone: synthesis, characterization and uses. Polym J. 1985;17:143–152. doi: 10.1295/polymj.17.143.

(2) Yousaf AM, Naheed F, Shahzad Y, Hussain T, Mahmood T. Influence of sodium starch glycolate, croscarmellose sodium and crospovidone on disintegration and dissolution of stevia-loaded tablets. Polim Med. 2019;49(1):19–26. doi:10.17219/pim/111516

(3) Berardi A, Bisharat L, Blaibleh A, Pavoni L, Cespi M. A Simple and Inexpensive Image Analysis Technique to Study the Effect of Disintegrants Concentration and Diluents Type on Disintegration. J Pharm Sci. 2018 Oct;107(10):2643-2652. doi: 10.1016/j.xphs.2018.06.008.