Polyvinylpyrrolidone (PVP), also commonly called polyvidone or povidone, is a water-soluble polymer compound made from the monomer N-vinylpyrrolidone.
International Numbering System (INS) for Food Additives: 1201
Food additives Europe numbers: E1201
Functional Category
Disintegrant; dissolution enhancer; suspending agent; tablet binder.
Applications in Pharmaceutical Formulation
Although povidone is used in a variety of pharmaceutical formulations, it is primarily used in solid-dosage forms. In tableting, povidone solutions are used as binders in wet-granulation processes.(2,3) Povidone is also added to powder blends in the dry form and granulated in situ by the addition of water, alcohol, or hydroalcoholic solutions. Povidone is used as a solubilizer in oral and parenteral formulations, and has been shown to enhance dissolution of poorly soluble drugs from solid-dosage forms.(4–6) Povidone solutions may also be used as coating agents or as binders when coating active pharmaceutical ingredients on a support such as sugar beads. Povidone is additionally used as a suspending, stabilizing, or viscosity-increasing agent in a number of topical and oral suspensions and solutions. The solubility of a number of poorly soluble active drugs may be increased by mixing with povidone. See Table II. Special grades of pyrogen-free povidone are available and have been used in parenteral formulations;
Description
Povidone occurs as a fine, white to creamy-white colored, odorless or almost odorless, hygroscopic powder. Povidones with K-values equal to or lower than 30 are manufactured by spray-drying and occur as spheres. Povidone K-90 and higher K-value povidones are manufactured by drum drying and occur as plates
Stability and Storage Conditions
Povidone darkens to some extent on heating at 1508C, with a reduction in aqueous solubility. It is stable to a short cycle of heat exposure around 110–1308C; steam sterilization of an aqueous solution does not alter its properties. Aqueous solutions are susceptible to mold growth and consequently require the addition of suitable preservatives. Povidone may be stored under ordinary conditions without undergoing decomposition or degradation. However, since the powder is hygroscopic, it should be stored in an airtight container in a cool, dry place.
Incompatibilities
Povidone is compatible in solution with a wide range of inorganic salts, natural and synthetic resins, and other chemicals. It forms molecular adducts in solution with sulfathiazole, sodium salicylate, salicylic acid, phenobarbital, tannin, and other compounds; see Section 18. The efficacy of some preservatives, e.g. thimerosal, may be adversely affected by the formation of complexes with povidone.
Safety
Povidone has been used in pharmaceutical formulations for many years, being first used in the 1940s as a plasma expander, although it has now been superseded for this purpose by dextran.(8) Povidone is widely used as an excipient, particularly in oral tablets and solutions. When consumed orally, povidone may be regarded as essentially nontoxic since it is not absorbed from the gastrointestinal tract or mucous membranes.(8) Povidone additionally has no irritant effect on the skin and causes no sensitization. Reports of adverse reactions to povidone primarily concern the formation of subcutaneous granulomas at the injection site of intramuscular injections formulated with povidone.(9) Evidence also exists that povidone may accumulate in the organs of the body following intramuscular injection.(10) A temporary acceptable daily intake for povidone has been set by the WHO at up to 25 mg/kg body-weight.(11) LD50 (mouse, IP): 12 g/kg(12)
Properties of PVP:
- Synthetic polymer: Made from repeating units of N-vinylpyrrolidone, it's a water-soluble material available in various grades with different molecular weights that influence its properties.
Limited Use in Food:
- Safety considerations: Though generally safe, PVP has low digestibility and may pass through the body unabsorbed. Regulatory bodies like the US FDA haven't designated it as generally recognized as safe (GRAS) for all food applications due to this factor.
- Alternatives: There are established food-grade excipients with a long history of safe use in food, making them the preferred choice for most food manufacturers.
More Common Applications of PVP:
PVP's versatility makes it valuable in other industries:
- Pharmaceuticals: A common excipient used for binding ingredients, stabilizing formulations, and controlling drug release in medications.
- Cosmetics and personal care products: Functions as a thickener, film former, and binder in various products.
- Industrial applications: Used in adhesives, coatings, and textile processing.
Potential, but Limited, Food Applications:
- Beverage clarification: Under strict regulations and limitations, some PVP grades might be approved to clarify juices or beverages by removing haze-causing particles.
- Film-forming agent: In specific cases, PVP could be used as a film-coating agent for certain food applications, but with very strict regulations.
Safety and Regulations:
- Limited approvals: Any use of PVP in food would require approval from regulatory bodies based on safety data, intended use, and the specific PVP grade.
- Stringent regulations: Due to safety considerations, permitted use of PVP in food would likely have strict limitations on the amount and specific applications.
Overall:
While PVP has some potential in food processing, its use is uncommon due to safety considerations and the availability of safer alternatives. Strict regulations would govern any permitted use of PVP in food.