Table IV.
Eleven Factors Studied in the Plackett–Burman DOE, and the Associated Treatment Levels
| Factor | Level (+1) | Level (−1) |
|---|---|---|
| X1 (A)—level of disintegrant gelatinization (categorical) | Partially gelatinized—Starch 1500 | Fully gelatinized—Spress® B825 |
| X2 (B)—tablet compression force (Pmax) (numerical) | 12 kN | 16 kN |
| X3 (C)—speed of granulator after roller compaction (numerical) | 50 rpm | 25 rpm |
| X4 (D)—roll pressure (dry granulation) (numerical) | 80 bar | 140 bar |
| X5 (E)—API particle size (categorical) | Cipro unsieved (d(0.5) = 15.47 μ) | Cipro sieved (d(0.5) = 8.87 μ) |
| X6 (F)—source/supplier of lubricant (categorical) | Vegetable source—Covidien | Animal source—Spectrum |
| X7 (G)—filler particle size (numerical) | Avicel PH 102 (90 μ) | Avicel PH 101 (50 μ) |
| X8 (H)—binder grade (hydroxypropyl cellulose) (categorical) | Low viscosity and small particle size—Klucel® EXF | Medium viscosity and larger particle size Klucel® JF |
| X9(J)—ratio of roll speed to feed screw speed (numerical) | Ratio = 5 (35/7) | Ratio = 7 (49/7) |
| X10(K)—blending time (API/excipient blend + lubricant blend + extragranular blend) (numerical) | 5 + 2 + 2 min | 20 + 2 + 2 min |
| X11(L)—glidant level (numerical) | No aerosil (0%) | Aerosil (0.25%) |