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

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 mu g 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 mu g 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.