Bioequivalence Studies for Two Different Strengths of Montelukast in Healthy Volunteers: 10 mg Film-coated Tablets and 5 mg Chewable Tablets

In order to assess the bioequivalence of 2 different formulations of montelukast, a pivotal trial for the montelukast 10 mg film-coated tablets formulation and a pivotal trial for the montelukast 5 mg chewable tablets formulation were conducted. For the 10 mg study, 34 healthy subjects were enrolled in a single centre, randomised, single-dose, open-label, 2-way crossover study, with a minimum washout period of 7 days, while for the 5 mg study, 42 healthy subjects were included in another study with a similar design. For both studies, plasma samples were collected up to 24 h post-dosing and drug levels were determined by reverse liquid chromatography and detected by tandem mass spectrometry detection. Pharmacokinetic parameters used for bioequivalence assessment, area under the concentration-time curve from time zero to time of last non-zero concentration (AUC_0–t) and from time zero to infinity (AUC_0–inf) and maximum observed concentration (C_max), were determined from the drug concentration data using non-compartmental analysis. In the 10 mg study, the 90% confidence intervals obtained by analysis of variance were 99.62–120.51% for C_max, 102.25–117.37% for AUC_0–t and 101.96–116.67% for AUC_0–inf, which were within the predefined acceptable range of 80.00–125.00%. In the 5 mg study, the 90% confidence intervals were 91.14–98.46% for C_max, 93.02–98.42% for AUC_0–t and 93.09–98.63% for AUC_0–inf, which were within the predefined acceptable range of 80.00–125.00%. Bioequivalence between formulations was concluded both in terms of rate and extent of absorption for both strengths.