Microneedles as an alternative technology for transdermal drug delivery systems: a patent review

ABSTRACT

Introduction: The most conventional drug delivery systems exist with limitations such as drug degradation, toxicity and low bioavailability. Also, hypodermic injections can cause pain, compromising patient compliance. Due to this, transdermal drug delivery systems can minimize several problems associated with conventional drug delivery. The development of microneedle arrays is an approach which allows drug delivery through the skin by improving safety, efficacy, and bioavailability. Hence, several studies have been searching for new ways of treatment using microneedle devices for transdermal drug delivery.

Areas covered: All patents were analyzed from European Patent Office and World Intellectual Property Organization databases that reported microneedle arrays using the combined keywords ‘microneedle’ or ‘microneedles’ and ‘drug delivery systems’. A total of 233 patents were analyzed, out of which 47 selected were microneedle devices for clinical applications.

Expert opinion: In past years, there has been a crescent of advances in the development of microneedles as a drug delivery system by researchers and pharmaceutical companies. The authors observed patents related to manufacture of dissolving, hydrogel-forming, solid, hollow, and coated microneedles for ocular and transdermal drug delivery. Finally, the authors noticed patents about new microneedle technologies with potential therapeutic application in several clinical conditions confirmed in clinical tests.

KEYWORDS:

• Transdermal drug delivery
• intradermal
• bioavailability
• biocompatibility
• fabrication
• microneedle
• skin

Article highlights

• TDDS have been overcoming conventional administration because it can prevent drug degradation, and also improve the bioavailability and provide sustained drug release.

• Microneedles are a painless technology for drug delivery into skin and cannot cause any discomfort and cross-infection compared to traditional needle stick injuries, allowing patient compliance to the treatment.

• Studies confirmed microneedles create pores through the stratum corneum barrier, allowing an effective transdermal and intradermal drug delivery.

• Academic researchers and pharmaceutical companies have patented microneedles formulations with potential transdermal drug delivery for a wide range clinical conditions.

This box summarizes key points contained in the article.

Declaration of Interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brazil (CAPES), National Council for Scientific and Technological Development – CNPq and FAPITEC-SE. The authors are kindly acknowleged funding agencies for providing grants supports.