Similarities between Wet granulation and Ruti cooking

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Actually, Pharmaceuticals processing and production have similarities to cook something. Some examples of that are, processing similarities between wet granulation and Ruti or Chapati cooking. Another example of this kind similarities are emulsion production with curry cooking. Though pharmaceuticals processing is similar to cooking but pharmaceuticals processing is done in the more precise, more controlled and more systemic ways to provide stability for prolong period.

Today I shall discuss about the similarities between pharmaceutical wet granulation process for manufacturing of tablet and Ruti or Chapati making.

Tablet is one of the most common unit dosage form. Tablet production can be done by 3 ways, those are Direct compression, Dry granulation and Wet granulation. Between these tablet production processing ways, wet granulation has similarities with Ruti or Chapati making.

Wet granulation is probably the most common means of tablet production. Among the tablet production process, wet granulation is the most time consuming, lengthy, most steps involving and expensive process but also most effective process for large size tablet production.

Ingredients used in Tablet production by wet granulation:

Active pharmaceuticals ingredients, diluents, binders, disintegrants, lubricants, glidants, anti-adhering agents

The steps of wet granulation are as follows:

  1. Dry mixing
  2. Wetting with binder solution
  3. Wet mixing
  4. Partial Drying
  5. Sizing
  6. Final drying
  7. Second or final mixing
  8. Tablet Compression

Details of wet granulation:

  1. Dry mixing

The Active Pharmaceutical Ingredient (API) is mixed with diluent, filler, disintegrant and dry binder in a Rapid Mixer Granulator for 10 to 15 minutes, mixing time depends on the different factors. This step ensures the homogeneity.

  1. Wetting with binder solution and wet mixing

After mixing the all the major ingredients in the first step, another major role playing ingredient that is binder solution is added in granulation process. This binder creates bonds between particles and forms agglomerates called granules. Actually these granules help in the flow of particles from hopper to feed frame because of increased gravitational force. Strength of tablet comes from binder that helps the tablet to with stand the mechanical strength during packaging and transportation. Sometimes only water is used as binder. Water is also used as solvent for binder solution preparation. Moisture sensitive product's binder is prepared by using Iso Propyl Alcohol. Actually, binder creates bridge between particles and forms granules.

After addition of binder solution wet mixing is done for 2 to 3 minutes. Sometimes binder solution has been added during mixing.

  1. Partial Drying : The wet granules are dried either using a tray drier or mostly fluidized bed drier. Drying granules in a tray dryer has some draw back. Tray dryer is a static process, so it requires granules bed agitation manually after certain period intervals. But in fluidized bed dryer, granules remains fluidized in the air because of high velocity air. So fluidized bed dryer is effective because all the surroundings of particles in a powder bed is in contact with the air. The hot air carries the moisture away from the granules, as a result the granules becomes dry.
  2. Sizing :The resultant product after drying, has been milled again to get smaller and uniform particle size. This uniform particle size is attained by desired screen size.
  3. Final drying :After obtaining the desired particle size, the granules are dried to desired moisture level. The average moisture level is 2-3%.
  4. Second/Final mixing: After attaining the desired particle size and desired moisture level a final mixing is done. At this stage, several ingredients like lubricants, disintegrants, glidants and sometimes some small quantity APIs are added etc. are added. The equipment are same a used in first mixing.


The final granular blend is now ready for compression and is compressed on a suitable tableting machine.

Ingredients of Ruti production:

Wheat flour 4 cups, Salt 1tsp & 1tsp Molasses.

Similarities between Wet granulation and Procedure for ruti cooking:

To collect wheat flour from wheat milling is done to get fine power. All the ingredients above are mixed together, as like dry mixing step of the wet granulation. After dry mixing, the mixture is added to the boiled water. Then wet mixing is done as like wet mixing of the wet granulation. The wheat powder itself acts as binder. After 5 minutes it is replaced from burner.Now the wet mass is rubbed around for 20-30 minutes. Then the wet mass is segmented according to size, thickness and shape of the ruti. Then the mass is spread with the help of cylindrical ballon that is made of wood. Now the ruti is backed in a tawa or pan by heat.

Summary of Wet granulation and Ruti cooking:

Sl No


Wet Granulation

Ruti Cooking


Mixing state of different ingredients

Powder state

Powder state


Dry Mixing

Dry Mixing is an essential part of wet granulation

Dry mixing is a step of ruti production


Wet mixing

Wet mixing is an essential and important mixing step.

Wet mixing is an important step


Partial Drying

Partial drying is done to help in attaining the desired granules size for drying enhancer

Actually, partial drying is not done for ruti production



By using a multimill, partially dried granules are sized to attain desired particle size.

There is no sizing step, but small ping pong ball size round wet mass is created. After special sizing, the balls shaped wet mass is spread as round full moon or other desired shape


Final drying

The granules are dried to attain a desired moisture level required for tableting

Now the wet mass is baked to form roti


Final mixing

Now the final dried granules are mixed with lubricants for easy ejection.

About the Author

Mumita Meshkat's picture
Author: Mumita Meshkat


Ph. Bhagavan P S RPh's picture

By experience, involvement and observation I strongly believe that a good pharmacist is and can be a good cook, after all any reciepe is nothing but a formulation!

Bhagavan P.S. B Pharm

Rtd. Dy Dir.(Pharmacy),Govt of Karnataka, India
Mumita Meshkat's picture

Yes you are absolutely right. But good pharmacists are more precise and maintain accuracy during tablet, capsule, oral liquid and other dosage form cooking. 

Ph. Bhagavan P S RPh's picture

Yes, medicine making needs absolute accurate measure and cooking needs approximate assessed measures.

Bhagavan P.S. B Pharm

Rtd. Dy Dir.(Pharmacy),Govt of Karnataka, India

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