Aram I. Ibrahim University of sulaimani College of pharmacy Industrial Pharmacy Granulation 2 Aram I. Ibrahim University of sulaimani College of pharmacy

Contents Introduction Advantages Method of preparation Dry granulation method Wet granulation method

Introduction Granulation is the process of collecting particles together by creating bonds between them, Bonds are formed by compression or by using a binding agent.

Introduction cont. Granules are dosage forms that consist of particles ranging from 0.2 to 4.0 mm, depending on the subsequent use of the granules. They are intended for oral administration. Some are swallowed as such, some are chewed and some are dissolved or dispersed in water.

Advantages To avoid powder segregation. To enhance the flow of powder. To produce uniform mixtures. To produce dust free formulations. To eliminate poor content uniformity. To improve characteristics of mixing.

Method of preparation Dry granulation method Wet granulation method without using a liquid solution. Wet granulation method addition of a liquid solution.

Dry granulation Dry granulation granules are formed generally without adding binding material by compaction. Dry granulation can well be applied in the case of moisture or heat sensitive or unstable materials.

Dry granulation Advantages Rapid method Requiring low energy No hydrolytic decomposition Heating can be avoided Needs few tools Small work place Expensive drying operations are avoidable

Dry granulation Disadvantages requires a special apparatus. The mechanical hardness of granules is lower. Product shows a heterogeneous particle size dispersion because of high proportion of powder material, thus has relatively unappropriate flowablity.

Dry granulation Dry granulation by briquetting Briquetting is a compressing operation, during which large size compressed material is performed as the first step. briquettes have approximately 20-30 mm diameter, flat and cylindrical shape with 5-15 mm thickness are produced by performing high compressing force.

Dry granulation Dry granulation by compactor Granulation is started with previously compaction of material. Granules are formed due to mechanical adhesion and compaction, compression, when compression forces act. Steps: 1) compaction 2) chopping 3) sieving

Wet granulation Wet granulation similar to dry granulation, starts also with preparatory operation of active substances and excipients (compounding, chopping, sieving). Firstly properties of active substance (e.g. dose, solubility, incompatibility, volume mass) should be considered at choosing granulation excipients.

Wet granulation Most frequently applied diluents during granulation: Lactose starch cellulose sucrose glucose mannitol sorbitol urea xylitol

Wet granulation Most commonly used binding materials, which create binding force between particles are the followings: 1) sugars sucrose glucose 2) polymers natural polymers gelatin acacia tragacanth starch Synthetic polymers EC MC CMC SCMC Water or ethanol can be used as a binding liquid also.

Steps in wet granulation Mixing of the drug(s) and excipients. Mixing of binder solution with powder mix. to form wet mass. Coarse screening of wet mass using a suitable sieve. Drying of moist granules. Screening of dry granules through a suitable sieve.

Steps in wet granulation Manual granulation oscillating granulator

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