Table 1.
Cannabidiol (CBD) solubility in tested solutions (S1–S4); solubility parameters of placebo vehicles (δ) and Δδ2 values; in vitro CBD skin permeation parameters (steady-state flux (J), cumulative permeated amount at 24 h (Qp,24), retained amount at 24 h (Qr,24) and Qr,24/J ratio of tested solutions (S1–S4), and vehicle formulations (F1–F3). Means ± SD (n ≥ 3).
| Vehicle | Solubility (mg/mL) | δ (cal/cm3) | Δδ2 (cal2/cm6) | J (μg/h/cm2) | Qp,24 (μg/cm2) | Lag time (h) | Qr,24 (μg/cm2) | Qr,24/J |
|---|---|---|---|---|---|---|---|---|
| S1 | 19.65 ± 0.40 | 7.09 | 16.5 | 0.99 ± 0.14 | 22.07 ± 3.92 | 1.79 ± 1.29 | 15.15 ± 4.02 | 15.28 |
| S2 | >300 * | 8.93 | 4.93 | 0.02 ± 0.01 | 0.31 ± 0.20 | >7 | 6.45 ± 3.23 | 351.13 |
| S3 | 16.23 ± 0.51 | 16.54 | 29.03 | 1.06 ± 0.34 | 23.05 ± 6.79 | 1.95 ± 0.79 | 37.81 ± 9.20 | 35.69 |
| S4 | 45.16 ± 1.04 | 13.34 | 4.35 | 0.03 ± 0.00 | 0.61 ± 0.04 | 3.37 ± 0.88 | 6.14 ± 1.46 | 207.45 |
| F1 | - | 7.61 | 12.56 | 0.34 ± 0.06 | 7.23 ± 1.24 | 2.95 ± 0.67 | 8.30 ± 1.96 | 24.34 |
| F2 | - | 16.51 | 28.72 | 1.28 ± 0.33 | 26.13 ± 7.24 | 3.84 ± 0.67 | 19.00 ± 5.31 | 14.89 |
| F3 | - | 10.37 | 0.62 | 0.04 ± 0.02 | 0.93 ± 0.28 | 3.88 ± 1.43 | 4.99 ± 1.64 | 113.6 |
* Indicative value (n = 1).