Fabrizia Mariotti

Simultaneous determination of levodopa methyl ester, levodopa, 3-O-methyldopa and dopamine in plasma by high-performance liquid chromatography with electrochemical detection.

A new procedure is described for the simultaneous determination of levodopa methyl ester (LDME) and its biotransformation products levodopa (L-DOPA), 3-O-methyldopa (3-OMD) and dopamine (DA) in stabilized plasma samples, using reversed-phase high-performance liquid chromatography. A coulometric detector equipped with a dual-electrode system operating in the redox mode was used to simultaneously quantitate all compounds. This system generated a double signal monitored by a dual-channel acquisition data system and allowed quantitation of compounds at the nanogram level. The intra- and inter-assay precision varied in the 2.4-6.9% and 3.2-9.1% ranges respectively, whereas the recoveries were close to 85% for L-DOPA and 3-OMD and 70% for DA and LDME. Samples may be stored at -80 degrees C for 15 days before analysis. The method was applied to plasma samples after oral administration of LDME to rats, but it may also be suitable for human pharmacokinetic studies.

Safety, pharmacokinetics, and pharmacodynamics of CHF 3381, a novel N-methyl-D-aspartate antagonist, after single oral doses in healthy subjects.

A double‐blind, randomized, placebo‐controlled study was performed to assess the safety, tolerability, and pharmacokinetics of single oral doses of CHF 3381 in 56 young healthy male volunteers. The central nervous system effects of CHF 3381 were also evaluated, as well as the effect of food on the rate and extent of CHF 3381 absorption. Seven doses of CHF 3381 (25, 50, 100, 200, 300, 450, and 600 mg) were evaluated in an escalating order. At each dose level, 6 subjects were given CHF 3381, and 2 subjects were given placebo. Safety and tolerability evaluation included adverse events, physical examination, vital functions, electrocardiogram, laboratory tests, and 24‐hour Holter (100‐mg and 450‐mg dose panels). Plasma and urinary concentrations of CHF 3381 and its two main metabolites (CHF 3567 and 2‐aminoindane) were measured with a validated high‐performance liquid chromatography method. Central nervous system effects were evaluated with the simple reaction time (SRT); learning memory task (LMT); Bond & Lader Visual Analog Scale for alertness, contentedness, and calmness; Addiction Research Center Inventory (ARCI); and electroencephalogram. There were no serious adverse events; the most frequent adverse events were dizziness, abnormal thinking, and asthenia. The number of adverse events with moderate intensity increased sharply with the dose, with no or few events up to 450 mg and 17 events with 600 mg. Therefore, 600 mg was defined as the maximum tolerated dose. There were no significant treatment effects on cardiovascular function and electrocardiogram parameters at any CHF 3381 dose or on oral temperature or laboratory tests. There were no clinically significant changes in laboratory variables. CHF 3381 was absorbed rapidly (tmax = 0.5–2 h) and cleared from plasma with a half‐life of 3 to 4 hours. Plasma levels of CHF 3381 and its two major metabolites were found to be proportional to the dose. 2‐Aminoindane formed slowly and reached much lower concentrations compared to the parent compound and the other metabolite (CHF 3567). Within 48 hours after dosing, 2% to 6% of the administered dose was found in the urine as unchanged drug, about 50% to 55% as the acid derivative (CHF 3567), and 2% to 3% as 2‐aminoindane. Ingestion of food did not affect the extent of absorption of the drug, while the rate of absorption was considerably reduced (tmax = 4 h). No significant effects of CHF 3381 were observed on attention (SRT) or memory (LMT). Visual analog scales revealed a decreasing effect of CHF 3381 on alertness at 1 hour that reached statistical significance at 300 and 600 mg. EEG spectral analysis revealed minor decreasing effects of the 200‐mg dose on total electric power measured at 2 hours. A stimulant effect was detected by the ARCI scale 24 hours after the 300‐mg dose and might be related to the slow formation of the 2‐aminoindane metabolite. In conclusion, this study has shown that the maximum tolerated dose of CHF 3381 after single oral administration in young healthy male volunteers is 600 mg. CHF 3381 displays linear pharmacokinetics in the dose range of 25 to 600 mg. The compound is rapidly absorbed and cleared from plasma with a half‐life of 3 to 4 hours. The ingestion of food seems to not affect the extent of absorption of the drug. Minor effects on the central nervous system were detected at doses equal to or greater than 300 mg.

A tolerability andpharmacokinetic study of a newinjectable formulation of disodium clodronate in healthyfemale volunteers

SummaryDisodium clodronate (dichloromethylene bisphosphonic acid, disodium salt; CAS 22560-50-5) is a bisphosphonate that has demonstrated efficacy in patients with a variety of diseases of enhanced bone resorption. Intramuscular clodronate can determine pain at the injection site, it is therefore particularly useful to co-administer a local anaesthetic with clodronate to reduce pain at the injection site. The tolerability and pharmacokinetic of a new formulation of 100 mg disodium clodronate containing 1% lidocaine (test formulation, ChiesiFarmaceutici S.p.A) were investigated incomparisonto the same formulation without thelocal anaesthetic (Clody®) and a marketed formulation containing1% benzyl alcohol (Clasteon®). Thirty healthy female volunteers were treated according to a single dose,double-blind, randomised, three-way cross-over design. The local tolerability was investigated by assessing reddening and hardening at the injection site, and plasma CPK levels. Pain intensity was investigated on the VAS (visual analogue scale) and on the VRS (verbal rating score). Urinary clodronic acid concentrations were determined using a validated specific GC/MS/NCI assay. The statistical analysis on pain assessment showed a significant reduction of pain intensity immediately and up to 2 hours after administration of the new formulation compared to the marketed ones. CPK levels and occurrence of hardening at the injection site did not show statistically significant differences between formulations. No local redness was reported. Clodronate urinary excretion during the 48 h collection interval was not statistically different among the formulations and the 95% confidence intervals were inside the bioequivalence acceptance region, demonstrating comparable bioavailability. It was concluded that the investigated new formulation of 100 mg disodium clodronate was better tolerated than the reference marketed formulations.

Bronchodilator efficacy of extrafine glycopyrronium bromide: the Glyco 2 study

An extrafine formulation of the long-acting muscarinic antagonist glycopyrronium bromide (GB) is in development for chronic obstructive pulmonary disease (COPD), in combination with beclometasone dipropionate and formoterol fumarate – a “fixed triple”. This two-part study was randomized, double blind, placebo controlled in patients with moderate-to-severe COPD: Part 1: single-dose escalation, GB 12.5, 25, 50, 100 or 200 μg versus placebo; Part 2: repeat-dose (7-day), four-period crossover, GB 12.5, 25 or 50 μg twice daily (BID) versus placebo, with an open-label extension in which all patients received tiotropium 18 μg once daily. On the morning of Day 8 in all five periods, patients also received formoterol 12 μg. In study Part 1, 27 patients were recruited. All GB doses significantly increased from baseline forced expiratory volume in 1 second (FEV1) area under the curve (AUC0–12h) and peak FEV1, with a trend toward greater efficacy with higher GB dose. All adverse events were mild–moderate in severity, with a lower incidence with GB than placebo and no evidence of a dose–response relationship. In study Part 2, of 38 patients recruited, 34 completed the study. Adjusted mean differences from placebo in 12 h trough FEV1 on Day 7 (primary) were 115, 142 and 136 mL for GB 12.5, 25 and 50 μg BID, respectively (all P<0.001). GB 25 and 50 μg BID were superior (P<0.05) to GB 12.5 μg BID for pre-dose morning FEV1 on Day 8. For this endpoint, GB 25 and 50 μg BID were also superior to tiotropium. Compared with Day 7, addition of formoterol significantly increased Day 8 FEV1 peak and AUC0–12h with all GB doses and placebo (all P<0.001). All adverse events were mild–moderate in severity and there was no indication of a dose-related relationship. This study provides initial evidence on bronchodilation, safety and pharmacokinetics of extrafine GB BID. Overall, the results suggest that GB 25 μg BID is the optimal dose in patients with COPD.

Safety, tolerability, and pharmacokinetics of single and repeat ascending doses of CHF6001, a novel inhaled phosphodiesterase-4 inhibitor: two randomized trials in healthy volunteers

Purpose The purpose of this study was to evaluate safety, tolerability, and pharmacokinetics (PK) of CHF6001, an inhaled phosphodiesterase-4 inhibitor. Materials and methods Two healthy volunteer, randomized, double-blind, placebo-controlled studies were conducted. In each, Part 1 evaluated single ascending doses, with PK sampling up to 48 hours post-dose; Part 2 evaluated multiple ascending doses (Study 1, 7 days; Study 2, 14 days), with PK sampling up to 24 hours post-dose on first and last day of each period. In Study 1, treatments were administered via single-dose dry-powder inhaler (SDDPI; Aerolizer): Part 1, 20, 100, 200, 400, 800, 1,600, and 2,000 µg or placebo; Part 2, 100, 300, 600, 1,200, and 1,600 µg or placebo once daily (OD). In Study 2, treatments were administered via multi-dose dry-powder inhaler (MDDPI; NEXThaler): Part 1, 2,400, 4,000, and 4,800 µg or placebo; Part 2, 1,200, 2,000, or 2,400 µg twice daily (BID) or placebo. Modeling and simulation then compared OD and BID dosing via MDDPI. Results There was a clear correlation between CHF6001 dose and plasma concentration, following single and multiple doses and using SDDPI and MDDPI. CHF6001 plasma concentration area under the curve (AUC) was dose proportional, with steady state slopes of the fitted line of 0.95 (90% CI: 0.86, 1.04) for AUC0–24 h in Study 1, and 0.85 (90% CI: 0.38, 1.32) for AUC0–12 h in Study 2. Bioavailability waŝ30% higher with MDDPI than SDDPI. The PK simulation confirmed dose proportionality; the same total daily dose OD or BID via MDDPI resulted in similar 24 hours exposure, with BID dosing providing smaller fluctuation and lower maximum concentration. CHF6001 was well tolerated with no relationship between dose and adverse events. Conclusion CHF6001 demonstrated a good safety profile. There was a clear dose proportionality for systemic exposure, with higher bioavailability via MDDPI, suggesting that the MDDPI provides better pulmonary drug deposition. BID dosing was associated with a better exposure profile.