Table 1.
In vitro release rate as a function of pod-IVR delivery channel configuration for a series of IVRs formulated using identical cores of 99.5% TDF and 0.5% magnesium stearate.
| Delivery Channel Size | Release Rate | |||||
|---|---|---|---|---|---|---|
| Polymer | Channels per pod |
Pods per ring |
Diameter (d) (mm) |
Area (A)a
(mm2) |
Total (mg d−1) |
per podb
(mg d−1) |
| PLA | 1 | 1 | 0.50 | 0.20 | 0.014 | 0.014 |
| PLA | 1 | 1 | 0.75 | 0.44 | 0.045 | 0.045 |
| PLA | 1 | 1 | 1.00 | 0.79 | 0.11 | 0.11 |
| PLA | 1 | 1 | 1.20 | 1.13 | 0.16 | 0.16 |
| PLA | 1 | 1 | 1.50 | 1.77 | 0.20 | 0.20 |
| PVA | 1 | 4 | 1.50 | 1.77 | 2.15 | 0.54 |
| PVA | 2 | 4 | 1.50 | 3.53 | 6.21 | 1.55 |
| PVA | 1 | 4 | 2.00 | 3.14 | 6.86 | 1.72 |
| PVA | 3 | 4 | 1.50 | 5.30 | 13.0 | 3.24 |
a
Calculated as A = π·(d/2)2
b
Calculated as total release rate divided by number of pods per ring.