Plasdone Polymers
ISP offers manufacturers of solid dosage forms comprehensive range of Plasdone polymers as binders for the development of tablet formulations whether manufactured by wet granulation, dry granulation or direct compression.

Application	Suggested Products	Compendial Name	Typical Use Level ( % w/w)	Advantages
Wet Granulation	Plasdone® K-25 Plasdone K-29/32 Plasdone K-90/K-90D	Povidone	1-5%	Highly efficient binding capacity at low use levels Reduces binder solution preparation time Low solution viscosity simplifies binder solution handling No impact on tablet dissolution
Dry Granulation	Plasdone S-630	Copovidone	1 to 10%	Excellent binding properties owing to high degree of plasticity Spherical spray-dried particles for excellent flow properties Increases tablet strength and reduces friability
Direct Compression	Plasdone S-630	Copovidone	1 to 15%

Plasdone K-90 and K-90D have the same molecular weight but differ by bulk density.

Wet Granulation
Wet granulation is the process by which powders are converted to granules with the desired properties to ensure good tablet production. An important consideration is selecting the optimum binder. 

Criteria for Selecting a Wet Granulation Binder

Criteria	Performance Impact
High cold water dispersibility and solubility	Fast solution preparation when binder is added to solution
Low viscosity solutions	Ease of handling and pumping of solution
High binding efficiency	Lower use levels. Tablets have higher breaking force and/or require lower compaction force
High water solubility	No impact on drug dissolution at high use levels

Plasdone polymers are the premier binders for wet granulation, offering the best combination of properties. Synthetic water-soluble homopolymers of N-vinyl-2- pyrrolidone, Plasdone polymers offer the following benefits in wet granulation:

• Highly adhesive polymers at low concentrations
• Soluble in cold water
• Excellent solubility in water and polar solvents
• Low solution viscosity for ease of use
• Nonionic
• Insensitive to pH and salts

Results from recent study are presented in a technical poster presented at the International Granulation Symposium.

Universal Wet Granulation Binder: Plasdone K-29/32 povidone

Selecting the proper Plasdone polymer depends on the desired tablet performance characteristics and processing conditions. Plasdone K-29/32 polymer is a commonly used and versatile binder. It offers the best combination of performance and ease-of-use. The advantages of Plasdone K-29/32 include:

• Faster polymer dissolution reduces binder solution preparation time
• Lower solution viscosity simplifies binder solution handling and pumping
• Higher binding capacity reduces binder use level and/or compression force –saving material costs, energy costs and tooling/equipment wear

The following use levels are suggested depending if binder is added directly to the active (dry blend) or dissolved in water and added from solution:

Product	Method of Binder Addition
	From Solution	Dry Blend
Plasdone K-29/32	3-5 w/w%	4-5 w/w%

Dry Granulation and Direct Compression

In direct compression and dry granulation tablet processes, binders with good dry binding properties are necessary. In addition, the binder must have exceptional flow properties to facilitate processing and ensure content uniformity.

Plasdone S-630 copovidone is an excellent tablet binder in dry granulation and direct compression tablet manufacturing processes as it:

• Improves compactability of other binders and fillers to increase tablet strength
  and reduces tablet friability
• Reduces tabletting compaction forces to reduce punch wear
• Solves direct compression formulation problems – increases tablet breaking forces

Plasdone S-630 has superior dry binding properties due to its relatively low glass transition temperature (Tg) which enables it to deform on compression and bind with other particles.  It also exhibits excellent plastic deformation on compression resulting in tablets with no stored stresses.

Depending on the tabletting process, the following guidelines will assist in formulation development:

Product	Compendial Name	Tablet Process
		Direct Compression	Dry Granulation
Plasdone S-630	Copovidone	1-15%	1-10%