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Significant differences between homozygous and heterozygous individuals were observed for all pharmacokinetic parameters. The AUC in the course of one those interval of 24 h (AUCtau), minium steady-state concentration (C(min)ss) and average steady-state concentration (C(av)ss) values for heterozygous individuals were more than twice those of individuals. Significantly higher values for C(max)ss, t1/2, half-value duration (HVD) and mean residence time (MRT) were also observed in heterozygous volunteers. The higher concentrations of metoprolol in heterozygous individuals also had pharmacodynamic consequences, namely, greater heart rate and blood pressure reduction.

Background and ObjectiveA novel tiotropium bromide monodose capsule dry powder inhaler (DPI) formulation and device have been developed. The formulation was based on a spray-dried matrix that enhances the aerosolizaton properties, allowing a less active tiotropium metered dose (13 µg/capsule) while maintaining the same delivered dose (10 µg/actuation). This study describes the pharmacokinetic bioequivalence to the reference product.MethodsThis randomized, two-stage, crossover, semi-replicate (three-way) study was performed in healthy volunteers. In each study period, subjects received a single dose of two capsules (20 μg delivered dose) of the study medication, separated by a 14-day washout period: tiotropium 10 μg delivered dose (Laboratorios Liconsa, Spain) and Spiriva HandiHaler® (Boehringer Ingelheim Pharma GmbH & Co KG, Germany). Blood samples were obtained up to 48 h post-dose to evaluate the comparative bioavailability. Tiotropium was measured in plasma by means of dual stage liquid–liquid extraction followed by the two-dimensional ultra-high performance liquid chromatography sensitive sub-pg/mL bioanalytical method. The main pharmacokinetic parameters were maximum plasma concentration (C max), area under the concentration–time curve (AUC) from time zero hours to the last observed concentration at time t (AUCt), and AUC from time zero hours to 30 min (AUC0.5). Bioequivalence was accepted if the 90.20 % confidence interval (CI) for the ratio test/reference of the primary pharmacokinetic parameters lay within the acceptance range of 80–125 %. Safety assessment was a secondary endpoint.ResultsA total of 30 subjects were randomized and bioequivalence was demonstrated for all primary pharmacokinetic parameters: C max (CI 87.26–106.60 %), AUCt (CI 101.33–111.64 %), and AUC0.5 (CI 97.95–113.49 %). Both study treatments were well tolerated (four non-serious adverse events [AEs] were reported in four subjects: one AE before any product administration, two AEs after test product administration; and one AE after reference product administration).ConclusionsBoth products containing tiotropium 10 µg delivered-dose DPI were bioequivalent and showed good tolerability and a similar safety profile.

A monocentric, open, randomised, single-dose, six-period crossover trial was carried out in healthy volunteers under fasting conditions to establish the most appropriate study design for a pivotal bioequivalence trial with acarbose (CAS 56180-94-0) regarding a) dosage of the drug, b) type of carbohydrate load, c) type of primary endpoint, and d) sample size. 50 g sucrose or 50 g starch were used as carbohydrate load. Acarbose was administered in doses of 50 and 200 mg. Blood glucose and breath hydrogen were evaluated as endpoints. Both acarbose doses reduced the effect of carbohydrate load. Blood glucose: no statistically significant difference could be noted between the overall effect of 50 mg and that of 200 mg acarbose irrespective of the type of carbohydrate load. Breath hydrogen: an influence could be shown only for sucrose as carbohydrate load. Practically no effect was observed with starch. The overall increase of effect is by more than 200% with sucrose when the dose of acarbose increases from 50 to 200 mg. This difference between the effects of both doses of acarbose on breath hydrogen is statistically significant. For a pivotal trial, sucrose is the most appropriate type of carbohydrate load, baseline adjusted area under the breath hydrogen response is the most appropriate primary endpoint, and a dose of 100 mg acarbose is the most appropriate dosage. A total number of 100 subjects will be needed for proving pharmacodynamic equivalence between two acarbose products in a pivotal trial.

AIMSPlasma pharmacokinetics permit the assessment of efficacy and safety of inhaled drugs, and possibly their bioequivalence to other inhaled products. Correlating drug product attributes to lung deposited dose is important to achieving equivalence. PUR0200 is a spray-dried formulation of tiotropium that enables more efficient lung delivery than Spiriva ® HandiHaler ® (HH). The ratio of tiotropium lung-to-oral deposition in PUR0200 was varied to investigate the impact of particle size on tiotropium pharmacokinetics, and the contribution of oral absorption to tiotropium exposure was assessed using charcoal block. METHODSA seven-period, single-dose, crossover study was performed in healthy subjects. PUR0200 formulations differing in dose and aerodynamic particle size were administered in five periods and Spiriva HH in two periods. In one period, Spiriva HH gastrointestinal absorption was blocked with oral charcoal. Tiotropium plasma concentrations were assessed over 8 h after inhalation. RESULTSPUR0200 pharmacokinetics were influenced by aerodynamic particle size and the ratio of lung-to-oral deposition, with impactor sized mass (ISM) correlating most strongly with exposure. Formulation PUR0217a (3 μg tiotropium) lung deposition was similar to Spiriva HH (18 μg) with and without charcoal block, but total PUR0200 exposure was lower without charcoal. The C max and AUC 0-0.5h of Spiriva HH with and without charcoal block were bioequivalent; however, Spiriva HH AUC 0-8h was lower when gastrointestinal absorption was inhibited with oral charcoal administration. CONCLUSIONSPharmacokinetic bioequivalence indicative of lung deposition and efficacy can be achieved by matching the reference product ISM. Due to reduced oral deposition and more efficient lung delivery, PUR0200 results in a lower AUC 0-t than Spiriva HH due to reduced absorption of drug from the gastrointestinal tract. British Journal of Clinical PharmacologyBr J Clin Pharmacol (2019) 85 580-589 580• Tiotropium is a commonly used bronchodilator used in the management of chronic obstructive pulmonary disease (COPD). • Tiotropium is used in clinical practice as Spiriva HandiHaler (HH), a lactose blend formulation with an 18 μg nominal dose, or Spiriva Respimat, a soft mist inhaler with a 5 μg nominal dose. • PUR0200 is a spray dried formulation of tiotropium that results in efficient lung delivery and similar bronchodilation to Spiriva HH with a 3 μg nominal dose. WHAT THIS STUDY ADDS• Tiotropium exposure following inhalation results from both lung and gastrointestinal absorption.• Tiotropium lung deposition and exposure is predicted by in vitro impactor sized mass as determined by cascade impaction.• Particle engineering approaches, such as PUR0200, enable multiple options for achieving bioequivalence, including formulations with similar lung doses and lower total systemic exposure. PUR0200 and tiotropium pharmacokinetics Br J Clin Pharmacol (2019) 85 580-589 581 PUR0200 and tiotropium pharmacokinetics Br J Clin Pharmacol (2019) 85 580-589 583