Pharmaceutical excipients: Characteristics
Why particle size and flow matter in tablet making
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.Excipients are judged on functional properties: particle size, flow, compressibility, moisture and purity. A change in grade or supplier can change a tablet's dissolution, so formulators qualify suppliers carefully.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Particle size and flow | grade-specific (e.g. MCC 50-180 micron grades, indicative) | compression and blend uniformity | indicative |
| Moisture | MCC typically at most 5-7% loss on drying (indicative) | API stability | indicative |
| Toxic impurities | DEG and EG at most 0.10% in glycerin (USP) | patient safety | USP |
Commercial grades
- Lactose monohydrate, anhydrous, spray-dried
- MCC PH-101, PH-102 and silicified MCC
- Pregelatinised starch
- HPMC film coatings
- Enteric methacrylates
- Croscarmellose sodium
- Magnesium stearate