PVP VA64 (CoPovidone) Pharma Grade API for Tablet / Capsule / Granule / Injection, Oral & Injectable is a linear random copolymer of N-vinylpyrrolidone and vinyl acetate in a nominal 60:40 ratio, CAS 25086-89-9. The compendial grade is controlled by Ph. Eur. 0685 and the USP-NF Copovidone monograph, with a K value range of 25.2–30.8 measured at 1% w/w in water and a pH of 3.0–5.0 for a 5% w/w aqueous solution. Vinyl acetate content is typically controlled between 35.3% and 41.4%, while nitrogen content is 7.0–8.0%. The material is freely soluble in water, ethanol, isopropanol, and dichloromethane, and practically insoluble in hydrocarbon solvents. The glass transition temperature is approximately 107 °C, lower than povidone K30 and consistent with the plasticizing contribution of the vinyl acetate units. This grade is supplied as a free-flowing powder with a loss on drying limit of 5.0% and a residue on ignition limit of 0.1%. Because the copolymer is hygroscopic but less moisture-retentive than povidone K30, controlled relative humidity and pre-drying are relevant variables in high-humidity production suites.

How Does the 60:40 Vinylpyrrolidone–Vinyl Acetate Ratio Modify Tablet Binder Performance?

The vinyl acetate units interrupt the hydrogen-bonding network of the pyrrolidone ring, reducing equilibrium moisture uptake at 25 °C/60% RH to approximately <5% w/w, compared with 15–20% w/w for povidone K30 under equivalent conditions. This compositional shift also lowers aqueous solution viscosity: a 10% w/w aqueous copovidone solution at 20 °C typically exhibits a Brookfield viscosity of 5–10 mPa·s, which permits higher solids loading and more uniform spray delivery in high-shear granulation. In wet granulation, copovidone is applied at 2–5% w/w dry basis as a binder solution of 5–20% w/w in water or hydroalcoholic mixtures. The copolymer forms interparticle bridges that increase granule strength without requiring excessive compression force. Tablet hardness is measured with a Schleuniger hardness tester according to USP <1217> or Ph. Eur. 2.9.8, while disintegration is assessed by USP <701> and Ph. Eur. 2.9.1. Dissolution is determined by USP <711> and Ph. Eur. 2.9.3. Because copovidone does not form a tight gel layer, oral tablets containing 2% w/w binder generally disintegrate faster than hypromellose-based formulations of equal binder level, provided the same tablet porosity and compression force are maintained.

When Copovidone Replaces Povidone K30 or Hypromellose in Aqueous Granulation

In formulations where povidone K30 produces over-wetted granules or where hypromellose retards drug release, copovidone is selected as a lower-viscosity, alcohol-soluble alternative. Unlike povidone K30, the vinyl acetate fraction reduces the glass transition temperature from approximately 175 °C for the homopolymer to approximately 107 °C for copovidone, improving film flexibility and reducing the external plasticizer demand in tablet film coating. Unlike hypromellose, copovidone exhibits no thermal gelation point in aqueous systems, so coating solutions do not require chilled water. For direct compression, the deformation mechanism is largely plastic; compactability is lower than microcrystalline cellulose but greater than povidone K30 at equivalent use levels. On a rotary tablet press at compression forces between 8 kN and 20 kN, friability measured per USP <1216> is typically below 0.5% when copovidone is combined with microcrystalline cellulose and lactose. Published data for this specific configuration is limited; the stated range is a process window rather than a release specification. When compared with pregelatinized starch, copovidone provides higher binder efficiency at lower use levels, but it is more hygroscopic than starch under high-humidity storage.

In a high-shear granulator with a 25 L bowl, an impeller tip speed of 6–10 m/s, and a chopper speed of 1500–3000 rpm, aqueous copovidone binder at 10–15% w/w is sprayed through a two-fluid nozzle at 10–20 g/min until the wet mass reaches a targeted torque or power draw. The liquid addition endpoint is often controlled by real-time impeller power consumption; batch-to-batch variability in the copolymer loss on drying can shift the required water amount by 0.5–1.0%. Addition beyond the endpoint by 2–3% can produce oversized, dense granules and prolonged drying, while under-addition by the same margin can yield friable granules and subsequent tablet capping. Drying in a fluid-bed dryer at inlet air temperature 55–65 °C to a final loss on drying of 1.5–2.5% is typical. Granules are milled through a 1.0 mm screen; granule size distribution is measured by sieve analysis per USP <786> or Ph. Eur. 2.9.38. Bulk and tapped density are determined per USP <616> and Ph. Eur. 2.9.34. The resulting granules should have a Carr index below 18 to ensure acceptable flow into tablet presses or capsule dosators. Processing at relative humidity above 60% without pre-drying should be avoided because the powder can agglomerate in storage and alter the granulation endpoint.

When the copolymer is used as a carrier in hot-melt extrusion of poorly water-soluble actives, a co-rotating twin-screw extruder with an L/D ratio of 40:1 and screw speed 100–300 rpm is typically operated at barrel temperatures from 130 °C to 160 °C. The processing window is bounded at the lower end by the glass transition of 107 °C and at the upper end by the onset of thermal discoloration; sustained barrel temperatures above 180 °C may generate aldehydes and peroxides that degrade oxidation-sensitive APIs. Torque rises sharply when the melt temperature approaches the glass transition, and melt viscosity is influenced by residual moisture; pre-drying at 40–50 °C to <1% water is advised before extrusion. Extrudate particle size can be characterized by laser diffraction according to ISO 13320-1:2020, and amorphous content can be assessed by X-ray powder diffraction or modulated differential scanning calorimetry according to USP <941> or Ph. Eur. 2.2.34.

Film-Coating, Capsule Filling, and Direct Compression Processing Windows

For aqueous film coating, copovidone is dissolved at 10–20% w/w; a plasticizer such as polyethylene glycol 400 or triethyl citrate is added at 5–15% w/w of polymer solids to reduce film brittleness. Coating equipment is typically a side-vented pan with inlet air temperature 55–70 °C, product bed temperature 30–40 °C, and atomizing air pressure 1.5–2.5 bar. Film adhesion to tablet cores is checked by cross-hatch tape test per ISO 2409:2013. For hard gelatin or hypromellose capsule filling, granules prepared with 2–5% w/w copovidone show improved plug formation in dosator or tamping-pin machines; fill weight uniformity is assessed per USP <905> and Ph. Eur. 2.9.5. In direct compression, copovidone is usually included at 2–10% w/w as a dry binder, although its low glass transition temperature may cause punch sticking under high-speed tableting if the powder temperature exceeds 40 °C. Tablet tensile strength is calculated from hardness, thickness, and diameter; the result is interpreted using USP <1217> and ISO 18081 as applicable. Blending with strongly acidic or oxidizing excipients should be avoided; residual peroxides and aldehydes in the copolymer may react with primary amine or thiol-containing actives.

For oral and injectable dosage forms, the product may be used as a crystallization inhibitor and matrix former in solid dispersions or as a stabilizer in aqueous parenteral formulations. Injectable-grade material requires a bacterial endotoxin certificate according to Ph. Eur. 2.6.14 and USP <85>, with an acceptance limit agreed with the finished dosage form, commonly ≤6 EU/g for excipient use. Total aerobic microbial count is controlled to ≤100 CFU/g by Ph. Eur. 2.6.12 and USP <61>. For sterile manufacturing, copovidone solutions should be filtered through a 0.22 µm sterilizing-grade membrane and prepared under controlled endotoxin and particulate conditions. In injectable formulations, residual peroxides must be monitored because peroxide levels of ≤400 ppm may still degrade oxidation-sensitive active pharmaceutical ingredients. Published data for specific injectable formulation configurations is limited; compatibility with the active substance, buffer salts, and primary container components should be confirmed by forced degradation and container closure integrity studies.

Compendial Release Limits, Residual Peroxide Control, and Elemental Impurity Assessment

The material is released against pharmacopoeial limits. Identification is performed by infrared absorption spectrophotometry per Ph. Eur. 2.2.24 and the relevant USP-NF monograph method. K value is determined by viscosity according to Ph. Eur. 2.2.9 and ISO 1628-2. Peroxide content is controlled to ≤400 ppm, heavy metals to ≤10 ppm, and residue on ignition to ≤0.1%. Elemental impurities are assessed according to ICH Q3D and USP <232>/<233>; the product is typically suitable for oral and parenteral routes when the supplier certificate confirms Class 1 and Class 2A elemental impurity limits. Residual solvents are controlled under ICH Q3C and USP <467>.