Pharmacokinetics and Bioequivalence of a Generic and a Branded Budesonide Nasal Spray in Healthy Chinese Subjects

Abstract The aim of this study was to evaluate the pharmacokinetic bioequivalence of a generic budesonide nasal spray and a branded product in healthy Chinese subjects under fasting condition. A single‐center, single‐dose, randomized, open‐label, crossover study was conducted in 32 healthy Chinese subjects under fasting condition. The subjects were administered 256 μg of generic budesonide nasal spray (test drug) or branded budesonide nasal spray (RHINOCORT AQUA, reference drug), respectively. For each period, the subjects were administered with 64 μg of budesonide per spray and 2 sprays for each nostril followed by a washout period of 7 days. Plasma concentration of budesonide was determined by a validated high‐performance liquid chromatography–tandem mass spectrometry method. The pharmacokinetic (PK) parameters were calculated, and the bioequivalence was compared using the noncompartment model with the Phoenix WinNonlin 7.0 program. Results show that the 90% confidence intervals of the test/reference ratios of maximum concentration, area under the plasma concentration–time curve from time 0 to the last measurable concentration, and area under the plasma concentration–time curve from time 0 to infinity for the budesonide concentration were 84.8% to 102.7%, 84.6% to 94.4%, and 85.4% to 95.2%, respectively, all fall within the bioequivalent range of 80% to 125%. The test and reference budesonide nasal sprays were PK bioequivalents in healthy Chinese subjects with comparable PK parameters. No serious adverse events were reported, and the 2 products have a good and similar safety profile.