Solids 6 & 7

Use of granules

tablets, filler for capsules

Flowability of granules

↑particle size, ↓surface area, ↓cohesive forces, ↑flowability

Stability of granules

↓surface area, ↓exposure to air/moisture, ↑stability

Caking of granules

↑surface area, ↓cohesive forces, ↓caking

Wetability of granules

↓cohesive forces, ↑wetability

Wet method for granule preparation

use of moisture and binding agents to facilitate particle aggregation; sieved, and large particles are dried

Dry method for granule preparation

binding agents are incorporated into the powder formulation, compressed at high pressure, and granulated by mills

Compressed tablets

prepared with punches and dies under very high pressure to compact powder/granules

Molded tablets

prepared by forcing a dampened powder material into a mold and drying moist tablets

4 stages of compressed tablet manufacturing

1. filling

2. metering - remove excess

3. compression

4. ejection

What is the purpose of a multi-layer tablet with different APIs?

can administer multiple APIs at a time; maintain separation between volatile APIs

Tablet coating purpose

• provides strength

• protects drug from light/moisture/oxidation

• can modify drug release

• separates incompatible materials

• product identity/brand recognition

• reduces operator exposure to active substances

Enteric coating

prevents drugs from releasing in the stomach

Sugar coating

masks unpleasant tastes/odors; adds 30-50% extra mass to tablet

6 steps of sugar coating

1. seal tablet core

2. sub coating

3. smoothing

4. coloring

5. polishing

6. printing

Film coating

applies a single, thin polymer coat adding less than 2-3% extra mass to the tablet

Coating peeling cause

tablet core ingredients do not promote good coating adhesion; insufficient film strength

Coating roughness cause

coating formulation is too viscous, sprayed droplets dry too rapidly or spraying nozzle is too far

Coating sticking & picking defect cause

inefficient drying, low temp

Coating twinning cause

• inefficient drying

• shape of tablets is not appropriate

• too slow pan speed

Coating chipping cause

• high degree of attrition associated with the coating process

• low amount of polymers

• high pan speed

Coating cracking cause

• tablet core expands when exposed to typical coating process temperatures

• too dry

• too cold

Logo bridging cause

• logo design is inadequate for a film-coated product

• too high coating viscosity