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Background Epoprostenol sodium for injection is approved for the treatment of severe cases of primary pulmonary arterial hypertension. Currently, there are 3 approved formulations of this drug containing the same active ingredient (epoprostenol sodium) but differing with regard to excipients. When compared with epoprostenol sodium formulated with glycine-mannitol (epoprostenol GM), 2 new formulations of epoprostenol sodium, one formulated with arginine-mannitol (epoprostenol AM) and one formulated with arginine-sucrose (epoprostenol AS), have improved stability after reconstitution and dilution. The biocomparability of epoprostenol AM and epoprostenol GM, with regard to pharmacokinetic (PK), pharmacodynamic (PD), safety, and tolerability profiles, has been shown previously. Objective This study compared PK, PD, safety, and tolerability profiles of the 3 different formulations of epoprostenol sodium for injection. Methods This was a prospective, single-center, open-label, 2-period, 2-treatment, randomized, crossover, ascending dose study in 2 parts. Twenty healthy men in part 1 and 20 different individuals in part 2 received epoprostenol AM and epoprostenol AS and epoprostenol GM and epoprostenol AS, respectively, in a crossover fashion, as sequential IV infusions of 2, 4, 6, and 8 ng/kg/min for 2 hours each. In each part, the PK profile of epoprostenol was characterized via analysis of the concentration-time profiles of its 2 primary metabolites: 6-keto-prostacyclin F1α and 6,15-diketo-13,14-dihydro-prostacyclin F1α. The effect of the formulations was assessed using the 90% CI of the geometric mean ratio calculated for the exposure PK parameters. The PD variables cardiac output, cardiac index, and heart rate were assessed using echocardiography. Adverse events were recorded through the study. Results The plasma concentration versus time curves of epoprostenol AM and epoprostenol AS in part 1 and epoprostenol GM and epoprostenol AS in part 2 were similar in shape and almost superimposable. For each study part, the 90% CIs of ratios of geometric means for AUC 0−∞ of the assessed epoprostenol formulations were within the range for bioequivalence (0.8−1.25). The increases in cardiac output, cardiac index, and heart rate resulting from infusion with epoprostenol sodium were comparable between all formulations, with maximum values attained after 8 hours. Almost all study participants reported at least one treatment-emergent adverse event, the most common being headache, which was reported in 80% to 85% of study participants. Conclusions Overall, the PK, PD, safety, and tolerability profiles of the 3 formulations of epoprostenol sodium for injection are comparable and meet the criteria of bioequivalence. Australian New Zealand Clinical Trials Registry identifier: ACTRN12612001086853.

Background CRTH2 is a prostaglandin D 2 receptor that plays an important role in allergic inflammation. Setipiprant is a potent CRTH2 antagonist under development for the treatment of allergic diseases. Objective The aim of this study was to evaluate the tolerability and pharmacokinetics of a single oral dose of a setipiprant capsule (reference) and a tablet formulation. Methods This was an open-label, 2-period, 2-way crossover, randomized study in which 20 healthy women and men (1:1 ratio) received either 2 250-mg capsules or a 500-mg tablet of setipiprant. Subjects were between 18 and 45 years old, with a body mass index of 18.0 to 28.0 kg/m 2 . Differences in pharmacokinetics of setipiprant formulations were explored overall and by sex. Results All subjects completed the study. Both formulations were well tolerated, with headache the most frequently reported adverse event (25% of subjects), followed by flatulence (15%) and somnolence and fatigue (10%). The adverse event profile in men and women and between formulations was similar. The ratios of geometric means for C max (0.94; 95% CI, 0.79–1.12) and AUC 0–∞ (1.01; 95% CI, 0.92–1.12) were mostly within the limits of 0.80 to 1.25. When corrected for weight, the differences observed between sexes, within each treatment, for C max (capsules: 1.01; 95% CI, 0.71–1.44; tablet: 0.89; 95% CI, 0.62–1.26) and AUC 0–∞ (capsules: 1.12; 95% CI, 0.86–1.47; tablet: 0.96; 95% CI, 0.73–1.25) were minor. Conclusion Both the setipiprant formulations were well tolerated. Setipiprant pharmacokinetics were similar between formulations, overall, and between sexes. The new tablet formulation may constitute a valid alternative to the capsule formulation for later clinical development phases. ClinicalTrials.gov identifier: NCT01877629.

Background: Depression often coexists with a number of disease states, and patients with a diagnosis of depression often receive multiple medications. Thus, it is desirable to avoid coadministration of agents that have a potential for drug interactions in these patients. Although escitalopram and its metabolites are weak to negligible inhibitors of the cytochrome P450 (CYP) 3A4 isozyme and are therefore unlikely to affect plasma concentrations of ritonavir (a CYP3A4 substrate and prototype CYP3A4 inhibitor), ritonavir may potentially affect plasma concentrations of escitalopram, as CYP3A4 is partially responsible for conversion of escitalopram to its major metabolite, S -demethylcitalopram ( S -DCT). Objectives: The aim of this study was to investigate the potential for pharmacokinetic interaction between escitalopram and ritonavir after concomitant administration of a single dose of each in healthy young subjects. Methods: In this single-center, randomized, open-label, 3-way crossover study, subjects received each of the following: a single dose of escitalopram 20 mg, a single dose of ritonavir 600 mg, and single doses of both escitalopram 20 mg and ritonavir 600 mg. Blood was collected and plasma was analyzed for the pharmacokinetic parameters (maximum plasma concentration [C max ], time to C max [T max ], area under the plasma concentration-time curve, plasma elimination half-life, oral clearance, and apparent volume of distribution) of escitalopram, S -DCT, and ritonavir. Results: Of 21 subjects (11 men, 10 women; mean [SD] age, 28.4 [4.4] years) who were enrolled, 18 completed the study. After concomitant administration of escitalopram and ritonavir, no statistically significant differences were noted in the pharmacokinetics of escitalopram, with the exception of apparent volume of distribution, which was reduced by ∼10% ( P S -DCT were unaffected by coadministration of ritonavir, with the exception of T max , which was increased in the presence of ritonavir. The pharmacokinetic parameters of ritonavir were also unaffected by coadministration of escitalopram. Conclusion: In general, no pharmacokinetic interaction was observed between escitalopram and ritonavir in the present study.

Background: Citalopram tablets fulfill most dosing needs in the treatment of depression, but some patients may have difficulty swallowing tablets and thus may be less likely to comply with their medication regimen. A liquid formulation of citalopram could be beneficial for such patients. Objective: This study was undertaken to compare the pharmacokinetic profiles of oral solution and tablet formulations of citalopram in healthy volunteers. Methods: In this open-label, single-dose, randomized, crossover, bioequivalence study, healthy volunteers alternately received one 60-mg dose of citalopram as an oral solution (10 mg/5 mL) and one 60-mg dose as a tablet. Doses were separated by a 14-day interval. Results: Of 24 subjects enrolled (mean age 27 years), 24 (16 men and 8 women) received the citalopram oral solution and 23 (15 men and 8 women) received the tablet; 1 subject discontinued before receiving the tablet. Citalopram was rapidly absorbed, with peak plasma concentrations occurring at ∼4 hours with both formulations. The rate and extent of absorption were similar between the 2 formulations, and no statistically significant differences were observed in half-life or oral clearance between formulations. Similarly, the pharmacokinetic profile for demethylcitalopram (the major metabolite of citalopram) did not differ between the 2 formulations. Both formulations were well tolerated, with no serious adverse events reported. Conclusion: The oral solution and tablet formulations of citalopram 60 mg were determined to be bioequivalent in this population.