Developing and Evaluating Stable Microemulsion Systems for Potential Intranasal and Transdermal Application of...

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems

Background:

• Omeprazole, a gastric secretion inhibitor, suffers from poor stability, low bioavailability, and short half-life with oral administration.
• Developing alternative delivery routes is crucial to overcome omeprazole's pharmacokinetic limitations.

Purpose of the Study:

• To formulate and characterize nonionic microemulsions for omeprazole transdermal and intranasal delivery.
• To evaluate the in vitro and in vivo performance of these novel omeprazole delivery systems.

Main Methods:

• Formulation of omeprazole-loaded nonionic microemulsions with droplet sizes under 100 nm.
• In vitro assessment of droplet size, rheology, polydispersity index, and skin/epidermis permeation.
• In vivo evaluation of relative bioavailability in rats via intranasal, transdermal, and oral routes.

Main Results:

• Microemulsions exhibited favorable characteristics and facilitated omeprazole permeation through rat epidermis (flux: 0.86–9.945 µg·cm⁻²·h⁻¹).
• Full-thickness human and rat skin showed drug entrapment, indicating potential challenges for transdermal delivery.
• In vivo studies revealed significantly enhanced relative bioavailabilities: 332% for intranasal and 103% for transdermal compared to oral omeprazole.

Conclusions:

• Stable omeprazole-loaded microemulsions show potential as effective carriers for alternative drug delivery.
• Intranasal administration demonstrated superior bioavailability, while transdermal delivery requires further optimization.
• These microemulsions represent a promising strategy for improving omeprazole's therapeutic efficacy through non-oral routes.