Enhancement strategies for transdermal drug delivery systems: current trends and applications

Abstract

Transdermal drug delivery systems have become an intriguing research topic in pharmaceutical technology area and one of the most frequently developed pharmaceutical products in global market. The use of these systems can overcome associated drawbacks of other delivery routes, such as oral and parenteral. The authors will review current trends, and future applications of transdermal technologies, with specific focus on providing a comprehensive understanding of transdermal drug delivery systems and enhancement strategies. This article will initially discuss each transdermal enhancement method used in the development of first-generation transdermal products. These methods include drug/vehicle interactions, vesicles and particles, stratum corneum modification, energy-driven methods and stratum corneum bypassing techniques. Through suitable design and implementation of active stratum corneum bypassing methods, notably microneedle technology, transdermal delivery systems have been shown to deliver both low and high molecular weight drugs. Microneedle technology platforms have proven themselves to be more versatile than other transdermal systems with opportunities for intradermal delivery of drugs/biotherapeutics and therapeutic drug monitoring. These have shown that microneedles have been a prospective strategy for improving transdermal delivery systems. Graphical abstract

Recent advances in transdermal drug delivery systems: a review

“…Tape stripping is a commonly used minimally invasive method to test the penetration of topically applied formulations through the SC, where a layer of the SC is removed with an adhesive tape followed by examination of the skin layer on the adhesive tape (Fig. 5 ) [ 74 , 83 , 86 , 87 ]. The tape stripping process is performed after an appropriate incubation time post topical application of the test composition.…”

“…A Reproduced from [ 66 ], copyright permission by Springer Nature 2021. B Reproduced from [ 74 ], copyright permission by Frontiers Media 2019 …”

“…The two most common modalities of microscopy are confocal laser scanning microscopy (CLSM) and two-photon fluorescence microscopy (2-PFM) (Fig. 6 ) [ 58 , 68 , 71 , 72 , 74 , 80 – 87 , 90 ].

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“…A , B , C Reproduced from [ 29 ], copyright permission by American Chemical Society 2020. D Reproduced from [ 74 ], copyright permission by Springer Nature 2021. E Reproduced from [ 40 ], copyright permission by Elsevier 2010.…”

Recent Progress in Transdermal Nanocarriers and Their Surface Modifications

“…The penetration efficiency, including drug penetration depth and drug permeation amount, is the most critical parameter of the transdermal nanocarriers [ 65 ]. The drug transdermal diffusion pathways are mainly divided into two pathways: transappendageal pathway and transepidermal pathway [ 4 ].…”