A Simplified Rat Model for Studying Nasal Drug Absorption

Abstract

A simple and rapid rat model for studying nasal drug absorption was developed. In this model, a solution of the test drug, propranolol hydrochloride, was gradually deposited into the nasal cavity of an anesthetized rat through a PE-20 polyethylene catheter connected to a tuberculin syringe via a 30 gauge needle. The extent of drug bioavailability was assessed by measuring propranolol blood levels and the changes in heart rate. For comparative purposes, identical experiments were repeated using the intravenous route of administration, an established rat model requiring surgery, and the proposed model after tracheal cannulation and esophageal li-gation. Although the pharmacokinetic parameters for the various models tested indicated bioavailabilities that were quite similar to that obtained by the intravenous route of administration, the drop in heart rates appeared to be more pronounced with the proposed model than with any of the other two models. In addition to its simplicity, the proposed rat model represents a less stressful and more physiological means of delivering a drug by the nasal route.