Novel Design Approaches in the Fabrication of Polymeric Microarray Patches via Micromoulding.

Inken Ramöller,Abigail Bogan,Ana Cordeiro,Ryan Donnelly,Emma Mcalister

doi:10.3390/mi11060554

Abstract

The focus on novel systems for transdermal delivery of therapeutic agents has increased considerably over recent years, as this administration route comes with many advantages. Polymeric microarray patches (MAPs) are minimally invasive devices that enable systemic delivery of a wide range of drugs by overcoming the outer skin barrier. Conventionally, MAPs fabricated by micromoulding have a low needle density. In this study, the performance of hydrogel-forming MAPs cast using novel industrially manufactured micromoulds with a high needle density (600 needles/0.75 cm2) was compared to that of MAPs obtained using conventional moulds with a lower density (196 needles/0.89 cm2). Surrounding holders for micromoulds were designed for time-efficient fabrication of MAPs. The influence of needle densities on mechanical strength, insertion efficiency and in vitro permeation of ibuprofen sodium (IBU) was analysed. Insertion of both MAPs into an artificial skin model and neonatal porcine skin was comparable. No significant difference was observed in permeation studies of IBU (p > 0.05), with a delivery of 8.7 ± 1.7 mg for low-density and 9.5 ± 0.1 mg for high-density MAPs within 24 h. This highlights the potential of these novel micromoulds for manufacturing polymeric MAPs with a higher needle density for future applications.

Highlights

The focus on transdermal drug delivery systems is increasing considerably as they have several advantages compared to other commonly used administration routes
The aim was to investigate the impact of needle density on the mechanical strength and insertion efficiency of microarray patches (MAPs) and on their ability to deliver the low-molecular-weight model drug ibuprofen sodium (IBU) in an in vitro setting
Further studies will have to be conducted to gain an understanding of pharmacokinetic permeation profiles over longer periods of time and the feasibility of using these novel high-density hydrogel-forming MAPs for the sustained delivery of different therapeutic agents. This is the first time that hydrogel-forming MAPs have been cast using these industrially produced silicone micromoulds of novel geometry

Summary

Introduction

The focus on transdermal drug delivery systems is increasing considerably as they have several advantages compared to other commonly used administration routes. Parenteral administration, on the other hand, often requires skilled personnel and injections can lead to complications such as pain, haematoma, bleeding and nerve injuries if applied incorrectly [2]. This is why approximately 10% of the world population are affected by needle phobia [3]. Non or minimally invasive transdermal drug delivery systems can overcome these issues. Due to the nature of skin, only a few therapeutic agents are currently available as transdermal delivery systems in the form of transdermal patches. To overcome the outer barrier of the skin, the stratum corneum, and reach the systemic blood circulation, drugs need to have specific physicochemical properties, such as low molecular weight and lipophilicity [4]. Recent research has focused on novel delivery devices that can disrupt this barrier

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