Topic
Ungual
About: Ungual is a research topic. Over the lifetime, 166 publications have been published within this topic receiving 2240 citations.
Papers published on a yearly basis
Papers
TL;DR: The topical therapy of nail diseases, especially of onychomycosis, and to a smaller extent, of nail psoriasis, is desirable to avoid the side effects associated with their systemic therapy, to increase patient compliance and reduce the cost of treatment.
Abstract: The topical therapy of nail diseases, especially of onychomycosis, and to a smaller extent, of nail psoriasis, is desirable to avoid the side effects associated with their systemic therapy, to increase patient compliance and reduce the cost of treatment. Systemic therapy is however the mainstay of treatment due to the poor permeability of the nail plate to topically applied drugs. For effective topical therapy, ungual drug permeation must be enhanced. This can be achieved by disrupting the nail plate using physical techniques or chemical agents. Alternatively, drug permeation into the intact nail plate may be encouraged, for example, by iontophoresis or by formulating the drug within a vehicle which enables high drug partition out of the vehicle and into the nail plate. The physical techniques (manual and electrical nail abrasion, acid etching, ablation by lasers, microporation, application of low-frequency ultrasound and electric currents) and chemicals (thiols, sulphites, hydrogen peroxide, urea, water, enzymes) that have shown ungual enhancer activity are discussed in this review. Optimal drug formulation, while crucial to ungual drug delivery, is only briefly reviewed due to the limited literature.
151 citations
TL;DR: The aim of this article is to help distinguish those types of melanonychia that are worrisome and should lead to biopsy from those that are reasonably reassuring and need only be followed clinically.
115 citations
TL;DR: The enzyme, via its hydrolytic action on nail plate proteins, could increase ungual drug delivery through enhanced drug permeation through the hoof membrane.
102 citations
TL;DR: This is the first systematic critique encompassing the detailed aspects of transungual drug delivery, a promising avenue for researchers to develop novel formulations, augmenting pharmaceutical industries to commercialize the products for nail disorders.
Abstract: Topical therapy is at the forefront in treating nail ailments (especially onychomycosis and nail psoriasis) due to its local effects, which circumvents systemic adverse events, improves patient compliance and reduces treatment cost. However, the success of topical therapy has been hindered due to poor penetration of topical therapeutics across densely keratinized nail plate barrier. For effective topical therapy across nail plate, ungual drug permeation must be enhanced. Present review is designed to provide an insight into prime aspects of transungual drug delivery viz. nail structure and physiology, various onychopathies, techniques of nail permeation enhancement and in vitro models for trans-nail drug permeation studies. Updated list of drug molecules studied across the nail plate and key commercial products have been furnished with sufficient depth. Patents pertinent to, and current clinical status of transungual drug delivery have also been comprehensively reviewed. This is the first systemat...
99 citations
TL;DR: The potential to use human nail clipping swelling as a surrogate marker of PE activity for topical ungual drug delivery for in vitro nail permeation studies is illustrated.
Abstract: Targeting drug treatment to fungal infections that reside within or below the nail plate is problematic due to the highly restrictive barrier of the human nail. To optimise topical formulations for ungual drug delivery, inclusion of an effective penetration enhancer (PE) is imperative. At present, in vitro nail permeation studies can take weeks or months in order to obtain any meaningful data because the lack of a simple in vitro model to identify and develop nail PEs makes the selection and optimisation of novel PEs an empirical and inefficient process. The aim of this study was to compare three methods for pre-formulation screening of putative ungual PEs and then to select the most suitable technique for screening candidates that may enhance the permeation of therapeutic agents through the human nail. Three screening techniques were evaluated; nail swelling (weight increase of human nail clippings), horse hoof swelling (weight increase of horse hoof clippings) and nail penetration of a radiolabelled permeability probe. Four test PEs were evaluated using each screening method and nail swelling was identified as a simple, rapid, economic, relevant and reliable technique. This screen was then used to evaluate 20 potential PEs. Thioglycolic acid (TA), hydrogen peroxide (H2O2) and urea H2O2 produced the greatest nail weight increases; 71.0 ± 4.6%, 69.2 ± 6.6%, and 69.0 ± 9.9 respectively. To confirm the relationship between human nail swelling and altered ungual barrier function, a permeation study was performed in human nails using caffeine as a model penetrant. Human nails pre-treated with TA in vitro had a 3.8-fold increase in caffeine flux compared to the control (TA-free solution). This study illustrated the potential to use human nail clipping swelling as a surrogate marker of PE activity for topical ungual drug delivery.
96 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 12 |
| 2020 | 7 |
| 2019 | 4 |
| 2018 | 8 |
| 2017 | 8 |
| 2016 | 7 |