Povidone K30: properties, uses, pros, cons, safety

Povidone K30 (Crospovidone) or cross-linked polyvinyl N-pyrrolidone or PVP also known as polyvinylpyrrolidone, is a synthetic polymer widely used in pharmaceuticals, cosmetics, and personal care products. It acts as a binder, film-former, stabilizer, and thickening agent in various formulations. Povidone K30 is especially valued for its ability to improve the consistency and texture of products, enhance the adhesion of active ingredients to the skin or hair, and stabilize emulsions. In pharmaceuticals, it is commonly used as a binder in tablet formulations and as a stabilizer in liquid medications.

Chemical Composition and Structure

Povidone K30 is a water-soluble polymer made from vinylpyrrolidone monomers. The "K30" in its name refers to its molecular weight, indicating the viscosity of the solution it forms. The polymer structure of povidone allows it to form films, bind components, and stabilize formulations. Its excellent solubility in water makes it versatile for use in various aqueous and non-aqueous systems.

Physical Properties

Povidone K30 typically appears as a white or off-white powder or granules, easily dissolvable in water and ethanol. It forms a clear, viscous solution upon dissolution and acts as a good film-former and stabilizer. It is non-toxic, non-irritating, and compatible with a wide range of ingredients, making it ideal for use in cosmetics, personal care, and pharmaceutical products.

The name describes the structure of the molecule

• Povidone - Another name for polyvinylpyrrolidone.
• K30 - Indicates the molecular weight grade of the polymer.

Description of raw materials used in production

• Vinylpyrrolidone monomer (N-vinyl-2-pyrrolidone) - The primary raw material for the production of PVP.

Synthesis process

• Radical polymerization - The vinylpyrrolidone monomer undergoes radical polymerization, often using peroxides as the initiator, to form the PVP polymer of varying chain lengths.
• Isolation and purification - The resulting polymer is then isolated, purified, and dried to yield the desired grade of povidone, in this case, K30.

The PVP K series includes: K12, K15, K17, K25, K30, K60, K90.

Applications

• Tablet Binder - Used in pharmaceutical products as a binder in tablets to enhance tablet compression and disintegration.
• Solubilizing Agent - Increases the solubility of poorly water-soluble compounds, thus improving their bioavailability.
• Film-forming Agents - In cosmetic products, Povidone K30 is often used as a film-forming agent, for instance, in hair styling products like gels or sprays.
• Suspension Stabilizer - Can stabilize suspensions in pharmaceutical or cosmetic preparations.
• Viscosifying Agent - Used to increase the viscosity of aqueous solutions or other vehicles.

Crospovidone type A (and type B) is a cross polymer consisting of N-vinylpyrrolidone, often referred to as insoluble PVP or cross-linked PVP. Insoluble in water, acid, alkalis and common organic solvents . It is a light yellow or white hygroscopic powder, practically odourless. Insoluble in water, acid and alkali and in all other common solvents.

Both Crospovidone type A and Crospovidone type B have the characteristic of swelling and leading to the formation of coordination compounds such as polyphenols, carboxylic acid and other low molecular weight compounds. The difference between the two lies in the different density, which leads to sometimes different applications. The higher the density, the finer the powder.

Tablet compactability. Fine crospovidone grades (type B) increase the tensile strength of tablets at a given compressive pressure. The finer the crospovidone grade, the stronger the bonding capacity.

Tablet compression. Both type A and type B have similar compression values.

Tablet bonding. Copovidone, as a dry binder, increasing the strength of the tablet slows its disintegration. In this case Crospovidone type B can provide rapid disintegration.

What it is used for and where

Medical

By the pharmaceutical industry due to its characteristics of physiological inertness, excellent solubility, film-forming capacity, chemical stability, and biological compatibility, it is used as a medical slow-release carrier, disintegration agent, haemodialysis film, etc. Depending on the ingredients in the formula, the disintegration time of capsules and tablets changes.

The low molecular weight PVP K series serves as a solubilising agent, suspension stabiliser and crystallisation inhibitor in ophthalmic and injectable formulations.

It acts in different ways:

• Disintegrating in solid tablets due to its ability to absorb water and swelling. Crospovidone is inert and has the same chemical structure as povidone, which is used as a carrier in solid dispersion systems. It improves dissolution and bioavailability.
• Complexing agent for tannin and polyphenols in alcoholic extracts or aqueous herbs.
• Suspension stabiliser increases the dispersion capacity of the solution sediment by acting as a hydrophilic viscosising polymer.
• Absorbs moisture

Crospovidone type A is also incorporated into medicinal tablets as a normal binding agent.

Crospovidone type B increases the tensile strength of tablets at a given value of compressive pressure, and the finer the grade of crospovidone, the greater the binding capacity.

Food

In the beverage industry, beer, fruit juices etc., Crospovidone type A has the property of maintaining taste, removing anthocyanin and polyphenol, improving colour and clarity of the liquid. it also acts as a preservative and stabiliser.

Cosmetics

Crospovidone type A acts as a moisturiser for the skin, maintains the moisture of higher grade cosmetics. In toothpastes it acts as a surfactant and alleviates inflammation.

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 stabiliser. Emulsions are thermodynamically unstable. Emulsion stabilisers improve the formation and stability of single and double emulsions. as well as their shelf-life. It should be noted that in the structure-function relationship, the molar mass of the ingredient used 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. In short, it allows physical control of the hairstyle.
• Viscosity control agent. It controls and adapts, Increasing or decreasing, viscosity to the required level for optimal chemical and physical stability of the product and dosage in gels, suspensions, emulsions, solutions. 

Health and Safety Considerations

Safety in Use
Povidone K30 is generally regarded as safe for use in pharmaceutical and cosmetic products. It is non-toxic, non-irritating, and hypoallergenic, making it suitable for a wide range of applications. It is commonly used in oral, topical, and injectable formulations, demonstrating a high level of safety across different use cases.

Allergic Reactions
Allergic reactions to Povidone K30 are rare, as it is considered a non-irritating and hypoallergenic ingredient. However, individuals with particularly sensitive skin are advised to perform a patch test before using products containing Povidone K30.

Toxicity and Carcinogenicity
There is no evidence that Povidone K30 is toxic or carcinogenic. It has been extensively studied and is considered safe at the concentrations used in pharmaceutical, cosmetic, and food products. It is also well-tolerated when administered orally, topically, or intravenously.

Environmental and Safety Considerations
Povidone K30 is considered environmentally safe, as it is easily degradable under normal environmental conditions. However, as with all synthetic polymers, it is important to dispose of products containing Povidone K30 responsibly to minimize environmental impact.

Regulatory Status
Povidone K30 is approved for use in cosmetics, pharmaceuticals, and food products by regulatory agencies such as the European Union and the Food and Drug Administration (FDA) in the United States. It is regulated to ensure that it is used in safe and appropriate concentrations across different products.

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

Crospovidone studies

• Molecular Formula    C₆H₉NO        C₆H₁₃NOP₂
• Linear Formula    (C₆H₉NO)_n
• Molecular Weight  111.14
• Exact Mass     111.068413
• CAS     25249-54-1  1-Vinyl-2-pyrrolidinone homopolymer (9003-39-8)
• UNII     4LFS24GD0V
• EC Number   201-800-4  607-660-4
• DSSTox Substance ID 
• IUPAC  1-Ethenyl-2-pyrrolidinone homopolymer
• InChl=1S/C6H13NOP2/c8-5-2-1-3-7(5)6(10)4-9/h6H,1-4,9-10H2
• InChl Key      LQIAZOCLNBBZQK-UHFFFAOYSA-N
• SMILES   C1CC(=O)N(C1)C(CP)P
• MDL number  MFCD00149016
• PubChem Substance ID    
• ChEBI  185135
• RTECS  TR8370000
• NCI    C80893
• RXCUI        1310706

Synonyms: 

• Vinylpyrrolidone
• Polyvinylpyrrolidone
• PVP
• Povidone
• 1-Vinyl-2-pyrrolidinone
• polyvinylpolypyrrolidone

Polyplasdone ; bolinan; colidon; dulcilarmes; hemodyn; kollidon; kollidon 12; kollidon 15; kollidon 17; kollidon 25; kollidon 30; kollidon 40; kollidon 90; kollidon cl; kollidon k30; kollidon k60; kollidon k90; luviskol k30; periston; periston n; plasdone; plasdone 25; plasdone 26 28; plasdone k 29-32; plasdone k 90; plasmosan; poly(n vinyl 2 pyrrolidone); poly(n vinylpyrrolidone); polyvidone; polyvidonk25; polyvinyl polypyrrolidone; poly(vinylpyrrolidone); polyvinylpyrrolidone; polyvinylpyrrolidone; polyvinylpyrrolidone 10 000; polyvinylpyrrolidone 11000; polyvinylpyrrolidone 25000; polyvinylpyrrolidone40000; polyvinylpyrrolidone 44 000; polyvinylpyrrolidone 700 000; polyvinylpyrrolidone solution; poridone; povidone 40; pvp 40000; pvp macrose; rp 143; subtosan; vinisil; 1 vinyl 2 pyrrolidinone polymer; kollidon k 30; polyvidon k25; polyvinyl pyrrolidone; polyvinylpyrrolidone 40000

References__________________________________________________________________________

Liu, Zhao-xia, Qi-lei CHENG, and Lan HE. Impact of the excipient povidone K30 on drug quality control of valsartan capsules. Chinese Journal of Pharmaceutical Analysis 34.6 (2014): 1091-1099.

Abstract. Objective: To confirm the origin and structure of the unknown substance,eluted at 0.14 fold of the relative retention time of valsartan peak (RRT=0.14),which was detected in related substances test of valsartan capsules;to explore the influence of the unknown material on the quality of valsartan capsules,and to provide basis for the revision of the quality standards. Methods: The analysis was carried out on an Inertsil ODS-4 column(250 mm×4.6 mm,5μm)with a mobile phase of acetonitrile-water-glacial acetic acid(500: 500: 1)at a flow rate of 1 mL·min-1.The detective wavelength was set at 225 nm.UPLC-MS,IR,1H-NMR and MALDI-TOF-MS techniques were applied to confirm the origin and structure of the unknown substance. Results: The unknown substance was confirmed to be the excipient povidone K30(PVP K30). Conclusion: The excipient PVP K30 peak is not to be counted as the related substance of valsartan capsules,and it should be specified to deduct the excipient peak in ChP 2010 to eliminate the influence on the result of determination.

Phadke C, Sharma J, Sharma K, Bansal AK. Effect of Variability of Physical Properties of Povidone K30 on Crystallization and Drug-Polymer Miscibility of Celecoxib-Povidone K30 Amorphous Solid Dispersions. Mol Pharm. 2019 Oct 7;16(10):4139-4148. doi: 10.1021/acs.molpharmaceut.9b00452.

Abstract. In the present study, we have investigated the variability in physical properties of povidone K30 (PVP K30) and its impact on crystallization and drug-polymer miscibility of celecoxib-PVP K30 (CLB-PVP K30) amorphous solid dispersions (ASDs). CLB-PVP K30 ASDs were prepared using nine batches of PVP K30, in situ on glass slides by quench-cooling using the hot and cold stage of a microscope. Crystallization of the ASDs stored at 40 ± 2 °C/75 ± 5% relative humidity was captured using polarized light microscopy for up to 24 h and quantified using mean pixel counts of images. The quantitative drug-polymer miscibility of nine CLB-PVP K30 systems was determined using melting point depression. Pearson's correlation analysis was used to find the correlation between (i) % crystallization with drug-polymer miscibility and physical properties and (ii) drug-polymer miscibility and physical properties, of PVP K30. The % crystallization was significantly variable (p < 0.05) among the nine CLB-PVP K30 ASDs. The nine PVP K30 batches exhibited significant variability (p < 0.05) from batch to batch and/or source to source in physical properties. The % crystallization showed correlation to particle size distribution (PSD) (weak positive), glass transition (Tg) (weak positive), drug-polymer miscibility (moderate negative), true density, and porosity (moderate positive) and hygroscopicity (strong positive). Miscibility showed correlation between Tg (weak positive), hygroscopicity (weak negative), PSD (moderate negative), and true density and porosity (strong negative). The study suggests PSD, hygroscopicity, true density, and porosity of PVP K30 as the functionality related characteristics for its intended functionality of physical stability when it is used as a stabilizer in ASDs.