Oral availability of bilastine

Bilastine (Bilaxten™) is a novel non-sedating H1 receptor antagonist (antihistamine) developed in the dosage form of oral tablets and indicated for the treatment of allergic rhinitis (seasonal and perennial) and urticaria. Several clinical trials have been performed in order to determine the efficacy and safety of bilastine. The aim of this trial was to study the absolute oral bioavailability of bilastine in humans.

Twelve male and female adults were recruited into a single centre for a randomized, single-dose, open-label, controlled two-arm crossover study with a minimum 14-day washout period between the two single doses. Two single doses of bilastine were administered: a 20-mg oral tablet and a 10-mg intravenous formulation. Blood and urine samples were collected between 0 and 72 h post each administration. The clinical trial was carried out under quality assurance and quality control systems with standard operating procedures to ensure that the study was conducted and data generated in compliance with the protocol, Good Clinical Practice standards, International Conference on Harmonisation and other applicable regulations.

Oral bioavailability of bilastine was 60.67 % with a 90 % parametric confidence interval of 53.79-67.56. The maximum bilastine concentration was measured 1.31 h after oral administration. Pharmacokinetic parameters were similar to those observed in previous studies. Tolerance to treatment was good, with no adverse events related to study medication.

The absorption of bilastine after oral administration to healthy subjects was rapid. The absolute oral bioavailability was moderate.