Bioavailability and pharmacokinetics of lorazepam after intranasal, intravenous, and intramuscular administration
Related Experiment Video
Updated: Jul 26, 2026

Intranasal Administration of CNS Therapeutics to Awake Mice
Published on: April 8, 2013
D P Wermeling1, J L Miller, S M Archer
1Drug Product Evaluation Unit of the University of Kentucky College of Pharmacy, Lexington 40536-0093, USA.
Abstract:
The purpose of this study was to evaluate the pharmacokinetic profile of intranasal lorazepam in comparison to currently established administration routes. Eleven healthy volunteers completed this randomized crossover study. On three occasions, each separated by a 1-week washout, subjects received a 2 mg dose of lorazepam via the intranasal, intravenous, or intramuscular route. Blood samples were collected serially from 0 to 36 hours. Noncompartmental methods were used to determine pharmacokinetic parameters. Lorazepam was well absorbed following intranasal administration with a mean (%CV) bioavailability of 77.7(11.1). Intranasal administration resulted in a faster absorption rate than intramuscular administration. Elimination profiles were comparable between all three routes. The concentration-time profile for intranasal delivery demonstrated evidence of a double peak in several subjects, suggesting partial oral absorption. Females were found to have significantly higher AUC values than males for all three delivery routes. Overall, this study demonstrated favorable pharmacokinetics of intranasal lorazepam in relation to standard administration methods. Intranasal delivery could provide an alternative, noninvasive delivery route for lorazepam.
Related Concept Videos
Additional Routes of Drug Administration
Administering drugs via inhalation allows for the direct delivery of gaseous, volatile substances or droplets to different parts of the respiratory tract. One of the advantages of the inhalation route is the rapid absorption of drugs into the circulatory system, which is possible because of the large surface area of...
Routes of Drug Administration: Parenteral
The intravenous route (IV) of drug administration can be further categorized into two types. The bolus injection administers the entire dose rapidly, while an intravenous infusion slowly delivers smaller doses steadily.
The IV route is often...
Bioavailability: Overview
Local Anesthetics: Pharmacokinetics
Non-Oral Extravascular Drug Absorption Routes
Lipophilic drugs that are stable at salivary pH (6) and exhibit minimal binding to the oral mucosa are absorbed more effectively...
Bioavailability: Overview

