Povidones are available in different molecular weights - the higher the molecular weight, the greater the viscosity and, consequently, the adhesive strength. The K-value denotes the intrinsic viscosity of the polymer related to the molecular weight and is derived from the relative viscosity of the aqueous solution measured at 25°C. The direct correlation between the molecular weight and properties enables the appropriate grade to be used in each formulation in the appropriate concentration to achieve the optimum effect.
To provide formulators with flexibility in the choice of wet granulation, JRS PHARMA offers three grades of wet binders: VIVAPHARM® PVP K25, VIVAPHARM® PVP K30, and VIVAPHARM® PVP K90.
Typical Relative Kinematic Viscosity for 10 g/l Solutions in water at 20°C
VIVAPHARM® PVP K25
24.0 - 27.0
VIVAPHARM® PVP K30
29.0 – 32.0
VIVAPHARM® PVP K90
85.0 – 95.0
VIVAPHARM ® PVP K30 and K25 are low viscosity wet binders with a good balance between adhesive strength and ease of handling. It is highly adhesive at low viscosity, thus offering the optimal balance between adhesive strength and ease of handling at 4-7% for VIVAPHARM® PVP K25 or 2-5% for VIVAPHARM® PVP K30. VIVAPHARM® PVP K90 can be added to the formulation in even lower percentages, such as 1-3%, due to its higher viscosity.
All VIVAPHARM® PVP grades have excellent solubility in water and a range of organic solvents and are supplied as a free-flowing powder with spherical particle morphology. This ensures rapid dispersibility and ultimate flexibility in the solvent of choice. Due to their non-ionic property, Povidones do not bear any risk of interaction with ionic APIs.