Absorption
Following a single dose administration of ella in 20 women under fasting conditions, maximum plasma concentrations of ulipristal acetate and the active metabolite, monodemethyl-ulipristal acetate, were 176 and 69 ng/ml and were reached at 0.9 and 1 hour, respectively.
Figure 1: Mean (± SD) Plasma Concentration-time Profile of Ulipristal Acetate and Monodemethyl-ulipristal Acetate Following Single Dose Administration of 30 mg Ulipristal Acetate
Table 2: Pharmacokinetic Parameter Values Following Administration of ella (ulipristal acetate) Tablet 30 mg to 20 Healthy Female Volunteers under Fasting Conditions| | Mean (± SD) |
| | Cmax (ng/ml) | AUC0-t (ng•hr/ml) | AUC0-∞ (ng•hr/ml) | tmax (hr)* | t1/2 (hr) |
| Ulipristal acetate | 176 (89) | 548 (259) | 556 (260) | 0.9 (0.5-2.0) | 32 (6.3) |
Monodemethyl- ulipristal acetate | 69 (26) | 240 (59) | 246 (59) | 0.9 (0.8-2.0) | 27 (6.9) |
Cmax = maximum concentration
AUC0-t = area under the drug concentration curve from time 0 to time of last determinable concentration
AUC0-∞ = area under the drug concentration curve from time 0 to infinity
tmax = time to maximum concentration
t1/2 = elimination half-life
* Median (range)
Effect of food: Administration of ella together with a high-fat breakfast resulted in approximately 40 - 45% lower mean Cmax, a delayed tmax (from a median of 0.75 hours to 3 hours) and 20 - 25% higher mean AUC0-∞ of ulipristal acetate and monodemethyl-ulipristal acetate compared with administration in the fasting state. These differences are not expected to impair the efficacy or safety of ella to a clinically significant extent; therefore, ella can be taken with or without food.
Distribution
Ulipristal acetate is highly bound (> 94%) to plasma proteins, including high density lipoprotein, alpha-l-acid glycoprotein, and albumin.
Metabolism
Ulipristal acetate is metabolized to mono-demethylated and di-demethylated metabolites. In vitro data indicate that this is predominantly mediated by CYP3A4. The mono-demethylated metabolite is pharmacologically active.
Excretion
The terminal half-life of ulipristal acetate in plasma following a single 30 mg dose is estimated to 32.4 ± 6.3 hours.
Drug interactions
CYP3A4 inducers: When a single 30 mg dose of ulipristal acetate was administered following administration of the strong CYP3A4 inducer, rifampin 600 mg once daily for 9 days, Cmax and AUC of ulipristal acetate decreased by 90% and 93% respectively. The Cmax and AUC of monodemethyl-ulipristal acetate decreased by 84% and 90% respectively [see Drug Interactions (7.1)].
CYP3A4 inhibitors: When a single 10 mg dose of ulipristal acetate was administered following administration of the strong CYP3A4 inhibitor, ketoconazole 400 mg once daily for 7 days, Cmax and AUC of ulipristal acetate increased by 2- and 5.9- fold, respectively. While the AUC of monodemethyl-ulipristal acetate increased by 2.4-fold, Cmax of monodemethyl-ulipristal acetate decreased by 47%. There was no in vivo drug-drug interaction study between ulipristal acetate 30 mg and CYP3A4 inhibitors [see Drug Interactions (7.1)].
In vitro studies demonstrated that ella does not induce or inhibit the activity of cytochrome P450 enzymes.
P-glycoprotein (P-gp) transporter: In vitro data indicate that ulipristal may be an inhibitor of P-gp at clinically relevant concentrations. When a single 60 mg dose of fexofenadine, a substrate of P-gp glycoprotein, was administered 1.5 hours after the administration of a single 10 mg dose of ulipristal acetate, there was no increase in Cmax or AUC of fexofenadine.
Breast Cancer Resistance Protein (BCRP) transporter: In vitro data indicate that ulipristal acetate may be an inhibitor of BCRP at the intestinal level.
The effects of ella on P-gp and BCRP transporters are unlikely to have any clinical consequences when considering ella's single dose treatment regimen, although there was no in vivo drug interaction study between ulipristal acetate 30 mg (ella) and substrates of P-pg and BCRP transporters.