Table 8.
Bioavailability of α-pinene and β-pinene.
| Exposure | Uptake | Distribution | Elimination | |||
|---|---|---|---|---|---|---|
| Exhale Air | Blood | Urine | ||||
| Inhalation (8 volunteers, with light exercise-50W) [81,95,96] | ||||||
| α-pinene (+) | 2 h 450, 225, or 10 mg/m3 | Relative net uptake 59–62% * | tmax 120 min cmax 20 µMol/L(for 450 mg/m3) cmax 10 µMol/L(for 225 mg/m3) (exposure concentration depended) * cmax 10 µMol/L |
7.7% |
cl21h 1.9 lkg−1h−1 |
0.001% In 30 min 4% of total uptake as cis and trans verbenol |
|
t1/2 (3 phases α, β, γ) α-4.8 min β-38 min γ-695 min | ||||||
| α-pinene (−) | 450 mg/m3 | 7.5% |
cl21h 1.16 lkg−1h−1 |
|||
|
t1/2 α-5.6 min β-40 min γ-555 h | ||||||
| β-pinene | 450 mg/m3 * | Relative net uptake 66% * | cmax 3 µMol/L * | * 5.7% |
* cl21h 0.5 lkg−1h−1 * t1/2 α-5.3 min β-41 min γ-25 h |
Not available |
| Dermal application in vitro [93], Ex vivo [92] | ||||||
| α-pinene | 1000 µL (concentration is not provided) for 27 h |
Papp 6.49 × 10−5 cm/s | ||||
| 100 mg/cm2 applied on 0.65 cm2 at 37 °C ¥ | cmax 40 µg/cm2 tmax 15 min in SC |
|||||
| β-pinene | 1000 µL (concentration is not provided) for 27 h |
Papp 4.48 × 10−5 cm/s | ||||
| 100 mg/cm2 applied on 0.65 cm2 at 37 °C ¥ | cmax 290 µg/cm2 tmax 60 min in SC |
|||||
| Oral administration (four volunteers) [89] | ||||||
| α-pinene | 9 mg (66 µmol) | Unmetabolized state—not detected (<4 µg/L) |
t1/2 MYR-1.7 h tVER-1.0 h cVER-0.8 h |
tmax 1.6 h (metabolites) |
||
|
tmax 1–3 h Metabolites |
t1/2 MYR-1.5 h cVER and tVER-1.6 h MYRA-1.4 h |
|||||
|
cmax MYR-11 µM tVER-26 µM cVER-9.3 µM |
cl24h MYR-1.5%, cVER-5.6%, tVER-4.1% MYRA-6.7%. |
|||||
| 78% unknown elimination, which could be exhalation or first-pass metabolism | ||||||
* Chamber vapour proportions α-pinene-54%, β-pinene-11%, 3-carene-35%; ¥ α-pinene 4.8%, β-pinene 1.1%, eucalyptol 3.3%, camphor 5.7%, and menthol 3.8%; trans-verbenol (tVER), cis-verbenol (cVER), myrtenol (MYR), myrtenic acid (MYRA), αPNM3, and αPN-M1, which are metabolites of α-pinene.