Granulation
What is Granulation. Why we need Granules. Types of granulation. Excepients. Modern Granulation techniques.
Granulation is the size enlargement process in which primary powder particles are made to adhere to form larger, multi particle entities called granules. It is the process of collecting particles together by creating bonds between them. Bonds are formed by Slugging (Dry Granulation) or Using a binding agent. (Wet Granulation)
WHY we prepare Granules when we have powders…….?
To enhance flow of powders. To avoid weight variation. To produce uniform mixture. To avoid poor content uniformity. To improve compaction. To produce dust free enviornment. To avoid powder segregation.
Wet Granulation Dry Granulation Direct Compression
Most widely used method. It involves addition of liquid solution to powder to form wet mass. When to use……. For the Products not degraded by Moisture Heat.
weighing Seiving Pre Mixing Kneading/Addition of binder Seiving of wet mass Drying of wet mass Seiving of dried mass Final Mixing
Weighing Acuretly weigh all the excepients and API. Sieving Sieving reduce particle size and ensure uniform mixing due to similar particle size. Increase surface area. Enhance rate of dissolution. Different seive numbers are used. Pre Mixing To achieve optimum mixing of different ingredients for wetting. Depends upon formulation API+diluents API+diluents+Disintegrents Equipment used are sigma mixer,cone mixer,high sher Granulators.
Addition Of Binder Binder may be in form of Solution (PVP in IPA) Suspension (HPC in IPA) Paste (Starch in Hot water) Solvent used should be Volatile Non Toxic Solvent With Or Without Binder Convert Powder into Wet mass. Equipment used are sigma mixer,Diosna mixer,High sheer Granulators.
Seiving Of wet Mass wet mass produced is not of uniform size. Wet mass is seived to obtain uniform size. To increase surface area of wet grains. Increased surface area results in decreased drying time. Drying of wet mass seived wet mass is dried either in FBD or Tray dryers Hot air evaporates solvent leaving behind dried grains.wet mass is dried untill residual moisture content 2-3% or according to specifications.
Seiving of Dried Mass Dried mass have not uniform size. Dried mass is seived to obtain uniform sized grains. Dried mass is passed throuhg a specified seive No.e.g 12,16,20 etc. For small size tablets higher seive no is used to facilitate uniform die filling. For large size tablet usually small seive no is used.(Exception Dissolution problem) Final Mixing Last step of wet granulation. Dried seived grains are mixed with specified exceptients e.g Disintegrants,colourants,Flavourants,Glidents or lubricants.
To enhance bulk weight. Examples Lactose Starch Manitol Dextrose DCP Disintegrents To break down tablets and granules. Examples Sodium Starch glycolate (Primojel) Crosslinked PVP Cross Carmilose Sodium (Ac Di Sol) Starch Cellulose Derivatives
Binders For binding the powder particles Examples Natural Semi Synthetic Synthetic Gums Methyl Cellulose PVP Starch HPMC Cellulose HPC Gelatin
Glidents Reduce inter particle friction. Enhance Flow. Examples Colloidal silicon dioxide (Aerosil) Lubricants Reduce friction between grains and machine Parts. Prevent sticking. Are of 2 types 1 Hydrophobic e.g Mg Stearate 2 Hydrophylic e.g Sodium steryl Fumarate
Amount Of binder Increased binder results in harder grains. Effect dissolution and D.T. Less amount of binder results fragile grains. Results friability and capping. Amount Of Solvent Higher quantity of solvent may cause Over wetting. Over wetting results in harder grains. Lower solvent quantity may cause under wetting. Under wetting results fragile grains. Increased amount of fines. Kneeding/Wetting Time Increased mixing time after addition of solvent results in harder grains.
Drying Time Over drying results friability and capping. Under drying results picking and sticking. Produce higher quantity of fine. Blending/Mixing Time Lower mixing time effects content uniformity. Prolong mixing results in segregation. Prolong mixing after hydrophobic Lubricants effects Disintegration and Dissolution.
Large no of materials can be granulated by this method. Higher quality grains are produced by this method. Wide range of excepients is available. Good content Uniformity. De-Merits Of Wet Granulation Large no of equipments are required. Time consuming, More exceptients needed. Coastly procedure.
What Is Dry Granulation It is the process in which granules are formed by the application of pressure. Pressure can be applied by using Rotery Compression or Chilsonater When to Use………. For Materials sensitive to Heat Moisture
Weighing Seiving Pre Mixing Formation Of Sluggs/Powder Sheets Screening of Sluggs/Powder Sheets Final Mixing
Weighing Acuretly weigh all the excepients and API. Sieving Sieving reduce particle size and ensure uniform mixing due to similar particle size. Increase surface are Enhance rate of dissolution Different seive numbers are used. Pre Mixing To achieve optimum mixing of different ingredients for slugging. Depends upon formulation API+diluents API+diluents+Disintegrents Equipment used are sigma mixer,cone mixer.
Formation Of Sluggs/Powder Sheets Fine powder is converted into grains by two methods Slugging (Large Size Tablets) chilsonator (Roller Compaction) Slugging (Large Size Tablets) Tablet press is used. Fine powder is converted into slugs by using flat punches and high pressure.
Chilsonater (Roller Compaction) Fine powder is converted into powder sheets. Two counter rotating rollers are used for pressure. Powder is passed through the rollers and the pressure of rollers convert fine powder into powder sheets. Screening of Sluggs/Powder Sheets Sluggs or powder sheets are crushed by using osscilating granulator or Fitz Petrik Mill to obtain grains.
Final Mixing Last step of Dry granulation. Seived grains are mixed with specified exceptients e.g Disintegrants,colourants,Flavourants,Glidents or lubricants. Exceptients For Dry Granulation Dilluents Disintegrents Glidants Lubricants
Less number of equipments are required. No Need of moisture and heat. Coast effective. De-Merits Of Dry Granulation. Pre compression is required. Produce dust.
When to use………. For crystalline materials. For free flowing materials. For materials having good compressibility properties. For direct compression granular exceptients are preffered e.g Lactose S.D,Avicel pH 102,200 etc. Steps For Direct Compression Weighing Seiving Mixing Compression
Simple,easy and quick. Require few exceptients. Time saving. coast effective. Demerits Of Direct Compression Segregation in hoper may occur. Flow problem may occur. Weight variation due to poor flow.
Steam Granulation Melt/Thermoplastic Granulation Moisture Activated Dry Granulation (MADG) Moist Granulation Technique(MGT) Thermal Adhesion Granulation Process Foam Granulation
for Feedback email@georgiaparvej@gmail.com
Comments