Complex Drug Delivery Systems: Controlling Transdermal Permeation Rates with Multiple Active Pharmaceutical...

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Transdermal drug delivery systems (TDDS) are crucial for systemic drug administration.
• Controlling the release profile of active pharmaceutical ingredients (APIs) is key for effective TDDS.
• Bilayer designs offer potential for improved control over drug release kinetics.

Purpose of the Study:

• To investigate the ability of bilayer TDDS to modulate the co-release of two fixed-dose APIs.
• To determine if spatial distribution and layer thickness in bilayer TDDS can independently control API permeation.
• To compare the performance of bilayer TDDS with a single-layer monolith design.

Main Methods:

• Fabrication of three distinct bilayer TDDS designs with varied layer thicknesses and drug spatial distribution.
• Utilizing Franz cell diffusion studies to assess API permeation rates.
• Comparing permeation profiles against a reference single-layer monolith TDDS.

Main Results:

• Bilayer TDDS designs successfully modulated API permeation compared to monolith designs.
• Achieved reduced opioid antagonist permeation while maintaining fentanyl permeation.
• Demonstrated independent control over each API's permeation by altering spatial distribution and layer thickness.
• Bilayer patch performance remained stable under accelerated stability storage for 8 weeks.

Conclusions:

• Modifying bilayer TDDS design enables individualized permeation control for each API.
• Spatial distribution and layer thickness are effective parameters for tuning drug release in bilayer TDDS.
• Bilayer TDDS offers a versatile platform for complex drug delivery applications with constant formulation composition.