Table III.
Physical Properties of Rifampicin-Loaded L-PLA Microparticles Prepared Using Various Polymer:Drug Ratiosa
| Polymer:drug ratio | Morphology | Yield, % | Drug content, % average (SD) | Loading efficiency, % average (SD) |
|---|---|---|---|---|
| 100% L-PLA | Discrete microparticles | 53.99 | – | – |
| 9:1 | Discrete microparticles | 39.86 | 3.34 (1.42) | 33.40 (14.18) |
| 8:2 | Discrete microparticles | 39.68 | 8.13 (0.29) | 40.64 (1.43) |
| 7:3 | Discrete microparticles | 39.75 | 16.33 (0.21) | 54.46 (0.70) |
| 6:4 | Discrete microparticles | 39.31 | 23.30 (0.79) | 58.25 (1.97) |
| 5:5 | Irregular microparticles | 35.50 | 41.52 (2.31) | 83.03 (4.62) |
| 4:6 | Agglomerated microparticles | 42.48 | 53.80 (1.16) | 89.67 (1.93) |
| 3:7 | Agglomerated microparticles | 39.82 | 64.21 (0.98) | 91.73 (1.40) |
| 2:8 | Agglomerated microparticles | 46.13 | 66.42 (5.70) | 83.02 (7.13) |
aOperating conditions: pressure = 172 bar, temperature = 40°C, concentration of solution = 20 mg/ml, and carbon dioxide molar fraction = 0.82