A.It is a white to yellowish powder made by reacting cellulose and propylene oxide (PO); the product of this reaction is hydroxypropyl cellulose (HPC).

Cellulose is insoluble in water, but by adding a hydroxypropyl cellulose group by reacting cellulose with PO, hydrogen bonding between hydroxyl groups in the cellulose is lessened, making it water-soluble.

A.It is used as a binder for nutraceutical tablets / granulation.

It can be used in various production methods, such as fluidized bed granulation,dry granulation, direct compression, twin screw extrusion, and film coating.
It can also be used as a thickener for coatings.

A.It exhibits “thermal cohesion.” HPC has a lower critical solution temperature (LCST) around 40-50℃ in water.

A solution of HPC becomes cloudy when heated above the "cloud point" (shown in the table below).
The viscosity will dramatically decrease.
This process is reversible, so when it is cooled down, it will return to its clear, colorless, high viscosity state.

*High molecular weight grades like VH has a lower cloud point than other lower molecular weight grades like SSL.

A.Yes, HPC has broad compatibility.

HPC is non-ionic and pH independent, so it can be used with a wide variety of active/functional compounds.
It also has a low peroxide value and is suitable for actives that are sensitive to oxidization.

A.It is fully soluble in water and polar organic solvents.

Water and alcohol can both be used as the solvent, so it is possible to select a solvent that is compatible with the characteristics of any active content.

When dissolving HPC in a mixture of ethanol and water, it will have a higher viscosity than HPC dissolved in water alone. An ethanol concentration between 20-40% yields the maximum viscosity. (Refer to the graph below)

A.Water or solvent should be stirred to create a vortex.

The dry HPC powder should be poured steadily into the vortex to create a dispersion. Once the powder is added, stirring speed can be reduced while HPC hydrates.

A.HPC has low moisture absorption.

HPC is less hygroscopic than other binders like HPMC and PVP.

A.Regular powder grades are recommended.

Regular powder grades hydrate slower than fine powders, so it is less likely to form lumps during dissolution.

A.It is important not to create lumps.

[Recommendation (1)]
When using room temperature water, stir the water thoroughly until a vortex forms, then add the HPC gradually.
This makes it possible to disperse the HPC quickly without forming large lumps.

[Recommendation (2)]
When blending highly concentrated or high viscosity HPC aqueous solution, use water with a temperature of 50℃ or above instead of room temperature water.
HPC disperses easily in hot water, regardless of the addition rate or product type, preventing the formation of lumps.

A.Once lumps form, it is difficult to dissolve them.

By heating it to above the cloud point, it will become easier to break apart lumps.(See Q3)
If lumps form, the only way to dissolve them is to keep mixing until the clumps dissolve.

A.You can adjust a solution to your desired viscosity by changing the amount you add, or the grade you use.

A.Hardness increases proportionally to HPC addition rate.Fine and Super Fine grades are more efficient.

Addition of even 1% SSL SFP improves hardness.
Very poorly compressible actives might require up to 10% HPC.

A.Low molecular weight grades like SSL have minimal impact on disintegration time.

Minimizing the amount of HPC in the formulation by using a high efficiency Super Fine Powder grade will enable fast disintegration.

A.The table below summarizes recommended grades for different uses.

A.The binder causes agglomeration of the powders and improves compressibility of the granules during tableting.

HPC binder decreases the granulation time, reduces granule friability,
and increases the hardness of tablets made from the granules.

A.It is possible to add it as either a powder or a solution.

Regular powder grades should be dissolved to use as a binder solution. Fine and Super Fine Powder grades can be dry mixed with other ingredients, and granulated with water or alcohol.

A.Increasing the molecular weight and viscosity of the binder solution causes more agglomeration.

Granulation occurs more readily, and tends to result in large granule size at higher viscosities.
It is also important to optimize the operation parameters of the granulation device.

A.It is recommended not to heat the binder,and to use it at a temperature below its cloud point.

If the solution reaches a temperature above its cloud point, thermal cohesion will occur, decreasing the viscosity of the solution, and thus it will not function as a binder.(See Q3)

A.Yes, it can be used as the primary polymer,or to modify HPMC-based coatings.

HPC can be used as a base for film coatings, or as a plasticizer.
When using it as a plasticizer for HPMC, HPC-SL is recommended.(See Q20-22)

A.They have low water-vapor permeability and oxygen permeability.

A.High strength films can be made.
Refer to the following table for details.

A.Using HPC-SL as a plasticizer can reduce tablet sticking.

A.This is because it has the highest surface area to mass ratio.

HPC-SSL SFP has the lowest viscosity and smallest particles size of all HPC grades.
The surface area available for binding is approximately 6 times that of a standard granule product.

A.Low addition rates of HPC have minimal impact on the flowability of the powder mixture.

We recommend adding only a small amount (2-5%) of HPC-SSL SFP for general direct compression, so the flowability of powder mixtures is dependent on the active ingredients and other ingredients.

A.Lactose has better flowability than MCC when combined with HPC-SSL SFP.

HPC-SSL SFP up to 10% has better flowability with lactose than in a mixture with MCC. In this addition range, there are no significant impacts to flowability.

Equipment : FT4 Powder Rheometer
Materials : Lactose or MCC (90,94,97,100％), SSL SFP (10,6,3,0％)
External variables investigated : Compressibility、Consolidation、Aeration

A.Online seminar or in-house seminar

The topics below are available for technical seminars at your facility. Some of the seminars have been recorded for online viewing.

A.Formulation design support

Please contact us for consultation on difficult formulations.

A.Observing experiments/video responses

Customer specific formulations can be evaluated at CTAC with your raw ingredients.
If it is unfeasible to come in person, we can live stream or take a video of the experiments and return prototypes.

A.Visit our website

Please send a request from this web page.
Our staff will send you the requested samples or documents.
We have two sizes of sample: 100g, and 1kg. (SFP only has one size:500g)
Also, you can look over technical documents.