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Open Access Highly Accessed Research article

Microneedle pretreatment enhances the percutaneous permeation of hydrophilic compounds with high melting points

Jessica Stahl*, Mareike Wohlert and Manfred Kietzmann

Author Affiliations

Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Foundation, Buenteweg 17, Hannover, 30559, Germany

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BMC Pharmacology and Toxicology 2012, 13:5  doi:10.1186/2050-6511-13-5

Published: 13 August 2012

Abstract

Background

Two commercially available microneedle rollers with a needle length of 200 μm and 300 μm were selected to examine the influence of microneedle pretreatment on the percutaneous permeation of four non-steroidal anti-inflammatory drugs (diclofenac, ibuprofen, ketoprofen, paracetamol) with different physicochemical drug characteristics in Franz-type diffusion cells. Samples of the receptor fluids were taken at predefined times over 6 hours and were analysed by UV–VIS high-performance liquid-chromatography. Histological examinations after methylene blue application were additionally performed to gather information about barrier disruption.

Results

Despite no visible pores in the stratum corneum, the microneedle pretreatment resulted in a twofold (200 μm) and threefold higher (300 μm) flux through the pretreated skin samples compared to untreated skin samples for ibuprofen and ketoprofen (LogKow > 3, melting point < 100°C). The flux of the hydrophilic compounds diclofenac and paracetamol (logKow < 1, melting point > 100°C) increased their amount by four (200 μm) to eight (300 μm), respectively.

Conclusion

Commercially available microneedle rollers with 200–300 μm long needles enhance the drug delivery of topically applied non-steroidal anti-inflammatory drugs and represent a valuable tool for percutaneous permeation enhancement particularly for substances with poor permeability due to a hydrophilic nature and high melting points.

Keywords:
Transdermal drug delivery; Microneedles; logKow; Melting point; Non-steroidal anti-inflammatory drug; In vitro permeation study; Physical penetration enhancement