Pharmacokinetics and Brain Targeting Characteristics of Risperidone Nasal Gel in Rats / 中国药学杂志

ABSTRACT

OBJECTIVE: To study the pharmacokinetics of risperidone (RIS) nasal gel and its brain targeting effect and related mechanisms in rats. METHODS: The concentrations of RIS in rat plasma and brain tissues were determined by HPLC method. The pharmacokinetics and relative bioavailability to oral RIS preparation of RIS nasal gel and the drug distribution in various brain tissues such as olfactory bulb (OB), olfactory tract (OT), cerebellum (CL) and cerebrum (CR) were investigated in rats. RESULTS: The main pharmacokinetic parameters of RIS following nasal and oral administration such as tmax and ρmax were 5 and 20 min, 9.89 and 1.93 μg·mL-1, respectively. The relative bioavailability of nasally administered RIS was up to 4 730%. Furthermore, the AUC values of RIS nasal gel for different brain tissues such as OB, OT, CL and CR were found to be 45.3, 9.9, 1.5 and 1.1 folds of those of oral drug suspension, respectively. CONCLUSION: The in vivo absorption rate and bioavailability of RIS following nasal administration are obviously increased and improved. Additionally, the significant brain targeting characteristics of the drug nasal gel is also confirmed.